CN107228338A - A kind of road lighting shape of a saddle LED lens and LED/light source - Google Patents

Abstract

The invention provides a saddle-shaped LED lens and LED light source for road lighting. The lens is a lens body composed of a bottom plane, a reflective curved surface and a saddle-shaped exit surface; The drum-shaped groove of the LED light source, the side wall of the drum-shaped groove is a fan-shaped surface, and the bottom wall is an arched quadratic surface. The light from the light source enters the main body through the top wall and side wall of the drum-shaped groove, and then is reflected by the reflective curved surface and refracted by the saddle-shaped exit surface to output a rectangular light spot. The invention has a large air contact area, is beneficial to solve the heat dissipation problem of LED lamp beads, and has uniform lighting spots, and can be widely used in the field of road lighting.

Description

A saddle-shaped LED lens and LED light source for road lighting

technical field

The invention belongs to the field of optical lenses and lighting, and in particular relates to a saddle-shaped LED lens and an LED light source for road lighting.

Background technique

With the development of semiconductor lighting technology, light-emitting diodes (Light Emitting Diode, LED) are more and more applied to street lighting. However, the high heat generation of LED street lights often leads to a sharp shortening of their life. How to effectively solve the heat dissipation problem of LED street lights is one of the current research topics. At present, street lamp lenses on the market are generally peanut-shaped, which has two problems: 1. The lens is thick; 2. The air contact area is small. The above two problems will make it difficult for the heat emitted by the LED chip to be exported from the lens, causing the local temperature of the LED light source to exceed its normal temperature range, resulting in many problems such as a decrease in the light output efficiency of the LED chip and a reduction in the service life, making the LED street lamp not normal and effective. ground use.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a saddle-shaped LED lens with small volume and large air contact area, which can effectively solve the problem of poor heat dissipation of LED street lamps in the prior art. It can produce rectangular spot lighting effects that meet the needs of actual road lighting.

In order to solve the problems of the technologies described above, the present invention is achieved through the following technical solutions:

A saddle-shaped LED lens for road lighting, characterized in that: the lens body of the lens is in the shape of a saddle extending along the X-X direction as a whole, the bottom surface (10a) of the lens body is a plane parallel to the X-Z plane, and the bottom surface (10a) is provided with a drum-shaped groove for placing the LED light source at the central position; the two ends of the lens body are reflective curved surfaces (21a), the top surface is the exit surface (20a), and the shape of the exit surface (20a) It is saddle-shaped, and the waist drum-shaped groove is used as the LED light source light guide groove, which is surrounded by two side walls (102a) and the top wall (101a) with the same shape; the side wall (102a) is parallel to the Y-Z plane Fan-shaped plane, the top wall (101a) is an arched quadratic surface, the side wall (102a) and the top wall (101a) of the waist drum-shaped groove are the light incident surface; After being refracted by the side wall, it reaches the reflective curved surface on both ends of the lens, and the light passes through the reflective curved surface to reach the saddle-shaped exit surface (20a), a part of the light reaches the saddle-shaped exit surface (20a) through the lens top wall (101a), and two parts of the light pass through After the above refraction and reflection, a rectangular light spot is formed on the target receiving surface.

Further, the contour line of the middle section of the saddle-shaped exit surface (20a) is a saddle-shaped curve symmetrical to the XY plane, and the cross-sectional contours of both ends of the saddle-shaped exit surface (20a) are semicircular, The saddle-shaped curved surface of the emitting surface (20a) is a curved surface formed by bridging the saddle-shaped curve gradually and smoothly transitioning to a semicircle toward both ends in the X-X direction.

Further, the profile line of the waist drum-shaped groove along the X-X direction is composed of a parabola opening towards the exit surface (20a) and two line segments parallel and symmetrical to the YZ plane, and the parabola conforms to the following expression :

Y ² =MZ ² +N

Among them, both M and N are not 0;

The top wall (101a) of the drum-shaped groove is an arch quadric surface formed by the parabola rotating around the X-axis.

Further, the profile line of the reflective curved surface (21a) along the X-X direction is composed of a section of conic curve, which is symmetrical with respect to the XY plane, and the reflective curved surface (21a) is rotated along the X axis by the profile line of the X-X direction Formed, the quadratic curve conforms to the following expression:

Y＝A+BX+CX ²

Among them, A, B, and C are not all 0.

Further, the middle position of the saddle-shaped curve is 0.42mm-0.46mm lower than the highest position of the two shoulders.

Further, the material of the lens body is polymethyl methacrylate (PMMA), polycarbonate (PC) or glass.

An LED light source comprising a saddle-shaped LED lens for road lighting according to any one of claims 1-7, wherein the LED light-emitting chip is located in the drum-shaped groove.

In the saddle-shaped LED lens for road lighting according to the present invention, the bottom surface of the lens body is a light-incident surface, the top surface of the lens body is a light-emitting surface, and the side wall of the lens body is a reflection surface. The waist-drum-shaped groove on the bottom surface of the lens body is a light guide groove, and the light guide groove is arranged facing the LED light source, and is surrounded by a side wall (102a), an identical side wall opposite to it, and a top wall (101a); The side wall (102a) of the light guide groove and its opposite side wall refract the light emitted by the LED light source (30) that deviates from the central axis of the LED light source (≥45°) toward the reflective curved surface (21a), and the top wall (101a ) to refract the light emitted by the LED light source that deviates from the central axis of the LED light source (<45°) towards the central axis, and the reflective curved surface is used to reflect the incoming light toward the saddle-shaped exit surface (20a) and make most of the light exit from the After the light is refracted and reflected, it forms a rectangular spot on the target receiving surface.

Compared with the prior art, the lens of the present invention has the following characteristics: 1. The present invention hollows out the outside of the reflective curved surface (21a) of the lens, reduces the thickness and volume of the lens, saves cost, and is suitable for market promotion; 2. Increase the contact area between the lens and the outside air. Therefore, the LED lens with this structure can enhance the heat dissipation effect of the LED lamp bead, and effectively solve the problem of poor heat dissipation effect of the LED street lamp in the prior art; 3. It can use the LED light source The emitted light is refracted and reflected to form a rectangular spot, which has good lighting effect and meets the needs of actual road lighting.

Description of drawings

Fig. 1 is an isometric test diagram of the lens of the present invention;

Fig. 2 is the X-X direction sectional view of the lens of the present invention;

Fig. 3 is a Z-Z direction sectional view of the lens of the present invention;

Fig. 4 is a side view of the lens of the present invention;

Fig. 5 is a bottom view of the lens of the present invention;

Fig. 6 is a schematic diagram of ray tracing in the Z-Z direction section of the lens of the present invention;

Fig. 7 is a schematic diagram of ray tracing in the X-X direction section of the lens according to the present invention;

Fig. 8 is a schematic diagram of the spot shape and illuminance distribution of the lens of the present invention;

Fig. 9 is a schematic diagram of the light distribution curve of the lens of the present invention;

Reference signs in the figure:

10a-bottom plane, 21a-reflective curved surface, 20a saddle-shaped exit surface, 101a-groove top wall, 102a-groove side wall, 30-LED light source.

Specific implementation method

In order to better understand the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the saddle-shaped LED street lamp lens according to the present invention has a saddle-shaped exit surface 20a; the lens bottom surface 10a is a plane parallel to the X-Z plane, and there is a drum-shaped groove in the center of the lens bottom surface 10a, namely The light guide groove is used to place the LED light source 30 and guide light from the light source to the lens. The sidewall (102a) of the drum-shaped groove and the sidewalls provided therein are fan-shaped planes parallel to the Y-Z plane, and the top wall (101a) thereof is an arched quadric surface. The profile line of the waist drum-shaped groove along the X-X direction is composed of a parabola opening towards the exit surface (20a) and two line segments parallel and symmetrical to the YZ plane, as shown in Fig. 2 and Fig. 3 . The parabola satisfies the following expression:

Y ² =MZ ² +N

Among them, both M and N are not 0;

The top wall (101a) of the drum-shaped groove is an arch quadric surface formed by the parabola rotating around the X-axis.

Both ends of the lens body are reflective curved surfaces (21a), the top surface is an outgoing surface (20a), the reflective curved surface 21a is symmetrically distributed along the YZ plane, and the shape of the outgoing surface (20a) is a saddle. The contour line of the middle section section of the saddle-shaped exit surface (20a) is a saddle-shaped curve symmetrical to the XY plane, and the cross-sectional profiles of both ends of the saddle-shaped exit surface (20a) are semicircular, and the exit The saddle-shaped curved surface of the surface (20a) is a curved surface formed by the saddle-shaped curve gradually and smoothly transitioning to a semicircle and bridging in the X-X direction to both ends, as shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4 .

FIG. 6 shows the light distribution principle of the saddle-shaped LED lens in the Z-Z direction of the saddle-shaped emitting surface 20a of the present invention. All the light emitted from the light-emitting surface of the LED light source, part of which is refracted by the two opposite side walls of the light guide groove, reaches the reflective curved surfaces of the two ends of the lens, and the light reaches the saddle-shaped exit surface (20a) through the reflective curved surface, and part of the light passes through the top of the lens The wall (101a) reaches the saddle-shaped exit surface (20a), and two parts of the light are distributed after the above-mentioned refraction and reflection, forming a rectangular light spot on the target receiving surface. Figure 7 shows the light distribution principle of the saddle-shaped exit surface 20a in the X-X direction. All the light emitted from the light-emitting surface of the LED light source is refracted by the two side walls and the top wall of the light guide groove, and then passes through the reflective curved surface 21a and the saddle-shaped exit surface. 20a performs light distribution. The side wall (102a) and the top wall (101a) of the drum-shaped groove are light incident surfaces. The light from the light source enters the lens body through the side wall (102a) and the top wall (101a) of the waist drum-shaped groove, and the side wall 102a of the waist drum-shaped groove and its oppositely arranged side walls deviate from the light emitted by the LED light source 30 Part of the light from the central axis of the LED light source (≥45°) is refracted to the reflective curved surface 21a, and then the light is reflected to the saddle-shaped exit surface through the reflective curved surface for light distribution, and the small angle (<45°) light emitted by the light source is directly After reaching the exit surface 20a through the top wall 101a, finally all light rays are refracted by the saddle-shaped exit surface (20a), and output a rectangular light spot on the target receiving surface. Fig. 8 is the saddle-shaped LED lens of the present invention, its light spot shape and illuminance distribution at the target receiving surface at a distance of 0.5 meters. Figure 9 shows its far-field light intensity distribution curves. There are two curves in total, one of which is distributed off-axis, and the other is distributed symmetrically with bat wings.

Through the principle of total reflection, the profile line of the reflective surface (21a) along the X-X direction is composed of a section of conic curve, which is symmetrical with respect to the XY plane, and the profile line of the reflective surface (21a) is formed along the X-X direction. Rotated by the X axis, the quadratic curve conforms to the following expression:

Y＝A+BX+CX ²

Among them, A, B, and C are not all 0.

Through the above design, the thickness of the lens is reduced, and it is easier to control the light path. Therefore, the saddle-shaped LED street lamp lens of the present invention has the following advantages: the overall volume and thickness of the lens are reduced, and the contact area with the air is increased, which is good for heat dissipation.

The material of the saddle-shaped LED lens is polymethyl methacrylate (PMMA), polycarbonate (Polycarbonate, PC) or glass.

The described embodiment is a preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation, without departing from the essence of the present invention, any obvious improvement, replacement or modification that those skilled in the art can make Modifications all belong to the protection scope of the present invention.

Claims (7)

1. A saddle-shaped LED lens for road lighting, characterized in that: the lens body of the lens is integrally in the shape of a saddle extending along the X-X direction, and the bottom surface (10a) of the lens body is a plane parallel to the X-Z plane, so The center of the bottom surface (10a) is provided with a drum-shaped groove for placing LED light sources, the side wall (102a) of the drum-shaped groove is a fan-shaped plane parallel to the Y-Z plane, and its top wall (101a) is arched A quadratic surface, the side wall (102a) and the top wall (101a) of the drum-shaped groove are light incident surfaces; the two end surfaces of the lens body are reflective curved surfaces (21a), and the top surface is an exit surface (20a), The shape of the exit surface (20a) is saddle-shaped; the drum-shaped groove is used as a light guide groove for the LED light source, and is surrounded by two side walls (102a) and a top wall (101a) with the same shape; the side wall (102a) is a fan-shaped plane parallel to the Y-Z plane, the top wall (101a) is an arched quadric surface, and the side wall (102a) and top wall (101a) of the waist drum-shaped groove are light incident surfaces; LED light source light Part of the light is refracted by the two opposite side walls of the light guide groove and reaches the reflective curved surfaces on both ends of the lens. The light passes through the reflective curved surface to reach the saddle-shaped exit surface (20a), and part of the light reaches the saddle-shaped exit surface through the lens top wall (101a). Surface (20a), two parts of the light rays form a rectangular light spot on the target receiving surface after the above-mentioned refraction and reflection. 2. The saddle-shaped LED lens for road lighting according to claim 1, characterized in that: the outline of the middle section of the saddle-shaped exit surface (20a) is a saddle-shaped curve symmetrical to the XY plane, Both ends of the saddle-shaped exit surface (20a) have a semicircular cross-sectional profile, and the saddle-shaped curved surface of the exit surface (20a) is gradually and smoothly transitioned to a semicircle and bridged by the saddle-shaped curve in the X-X direction to both ends composed surfaces. 3. The saddle-shaped LED lens for road lighting according to claim 1, characterized in that: the section contour line of the waist drum-shaped groove along the X-X direction is directed from a section of opening to the parabola of the exit surface (20a) and two Composed of line segments parallel and symmetrical to the YZ plane, the parabola conforms to the following expression: Y ² =MZ ² +N Among them, both M and N are not 0; The top wall (101a) of the drum-shaped groove is an arch quadric surface formed by the parabola rotating around the X-axis. 4. The saddle-shaped LED lens for road lighting according to claim 1, characterized in that: the profile line of the reflective curved surface (21a) along the X-X direction is composed of a section of quadratic curve, which is symmetrical with respect to the XY plane , the reflective surface (21a) is formed by rotating its profile line in the X-X direction along the X axis, and the quadratic curve conforms to the following expression: Y＝A+BX+CX ² Among them, A, B, and C are not all 0. 5. The saddle-shaped LED lens for road lighting according to claim 2, characterized in that: the middle position of the saddle-shaped curve is 0.42mm-0.46mm lower than the highest position of the two shoulders. 6. The saddle-shaped LED lens for road lighting according to any one of claims 1-6, characterized in that: the material of the lens body is polymethyl methacrylate (PMMA), polycarbonate (PC) or glass . 7. An LED light source comprising the saddle-shaped LED lens for road lighting according to any one of claims 1-6, wherein the LED light-emitting chip is located in the drum-shaped groove.