CN204404073U - A kind of high order aspect type direct-light type LED backlight illumination light-distribution lens - Google Patents

Abstract

The utility model relates to the technical field of backlights, in particular to a high-order aspect type direct-down LED backlighting light distribution lens. The light distribution includes a lens body, and the lens body includes an incident surface and an exit surface; wherein the surface types of the incident surface and the exit surface are high-order aspect types, and lenses with such high-order control surface types can effectively control The distribution of positively refracted light, especially the distribution of large-angle light, can better meet the needs of backlighting. The lens of the utility model can increase the distance between the LED light sources, reduce the number of LEDs, and shorten the distance between the LED light source and the diffusion plate under the premise of the same light output area and the same illuminance uniformity on the diffusion plate. The cost of the direct-lit LED backlight lighting system is reduced, and the volume is reduced.

Description

A high-order aspect type light distribution lens for direct LED backlighting

technical field

The utility model relates to the technical field of backlighting, in particular to a high-order aspect-shaped direct-down LED backlighting light distribution lens.

Background technique

At present, there are usually two types of backlighting methods and lighting structures for LED backlighting and LED panel lights used in LCD TVs: one is to place multiple LEDs on the side of the light guide plate (the optical axis of the LED is basically perpendicular to the side of the light guide plate), The light emitted by the LED enters the light guide plate through the side of the light guide plate. After multiple total reflections and refractions in the light guide plate, finally all the light is transmitted through the front of the light guide plate. By precisely controlling the ratio of reflection and refraction of the light guide plate, A uniform light-emitting surface can be formed on the front of the light guide plate; this method is often called a side-type lighting method. The other is to place multiple LED light sources on the back of the diffusion plate (in this method, the optical axis of the LED is basically perpendicular to the back of the diffusion plate). A secondary light distribution lens is placed between the plates, and the light distribution lens distributes the light emitted by the LED for a second time, and evenly illuminates the back of the diffusion plate; in this way, the light enters the inside of the diffusion plate through the back of the diffusion plate and diffuses again, from The front side of the diffuser plate emits light, which can form a uniform light emitting surface on the front side of the diffuser plate. This method is often called the direct lighting method.

Compared with the above two lighting methods, the same light output area is formed. The light travel path of the side entry type is much larger than that of the direct type, and the light output efficiency of the side entry type is low. Therefore, the side entry type lighting method has high energy consumption and high cost.

In recent years, with the further application and promotion of products such as LED backlighting and LED panel lights for displays (such as flat-panel TV displays). The energy-saving requirements and cost control requirements for corresponding products are also becoming more and more urgent; under such a background, the traditional side-type lighting method with low efficiency is gradually being replaced by the direct lighting method.

At present, the development trend of LED direct-lit backlighting is: to reduce the thickness from the LED light source to the diffuser plate (mainly to reduce the Small system volume), while ensuring the uniformity of irradiation. This puts forward higher requirements on the light distribution lens.

In the prior art, in order to increase the distance between the LEDs and compress the distance between the LEDs and the diffusion plate, as shown in Figure 1, some direct-type systems use reflective lenses to redistribute the light emitted by the LEDs. A considerable part of the light 120 emitted by the LED 110 is reflected by the lens 130 to the reflective layer 140 on the inner cavity of the system, and then reflected to the diffusion plate 150 . Although this lighting method can reduce the height of the space, it is highly dependent on the characteristics of the reflective layer. At the same time, it has high requirements on the surface accuracy and installation accuracy of the lens and the flatness of the reflective layer, so it is difficult to achieve uniform illumination.

There are also direct lighting systems that use refracting lenses to redistribute the light emitted by LEDs, but it is difficult to achieve uniform lighting when the distance between LEDs is large and the distance between LEDs and diffusers is small. One of the important reasons for uneven illumination is that the surface shape of the incident surface and the exit surface of the lens is relatively simple. The emitted light is difficult to effectively distribute in a large angle range according to the requirement of backlighting.

Utility model content

In order to achieve the above effects, the utility model provides a high-order aspect type direct-type LED backlight light distribution lens; by adjusting the surface shape of the outgoing surface and the incident surface, the light is distributed reasonably, and the premise of achieving the same illuminance uniformity The number of LED light sources used in the backlighting system can be reduced, and the thickness from the LED light source to the diffusion plate can be reduced, reducing the volume of the system.

In order to realize above-mentioned technical effect, the utility model takes following technical scheme:

In order to solve the above problems, the utility model proposes a high-order aspect type direct-type LED backlighting light distribution lens; it includes a lens body, wherein the lens body includes an exit surface, an incident surface and a bottom composite surface; the bottom composite surface Located at the bottom of the lens body, the side close to the central axis of the lens body is connected to the incident surface; the incident surface is located at the center of the bottom of the lens body and is concave toward the top of the lens body.

In the utility model, the surface shapes of the outgoing surface and the incident surface of the lens body are high-order curved surfaces. Among them, both the incident surface and the exit surface can be determined by the equation To describe, where c is the curvature of the vertex of the surface, k is the quadratic aspheric coefficient, r is the radial coordinate (r ² =x ² +y ² ), z is the axial coordinate, α _i is the i-term coefficient, and i is 1, 2, 3... natural numbers.

Further, at least one of the coefficients α _i in the terms of the expression i≧6 of the exit surface of the lens described in the present invention is not zero.

Further, at least one coefficient α _i in the terms of the incident surface expression i≥4 of the lens described in the present invention is not zero.

The lens with this high-order term control surface can effectively control the distribution of forward refracted light, especially the distribution of large-angle light, and can better meet the needs of backlighting.

Further, the bottom composite surface includes at least one sub-composite surface. When the sub-composite surface is cut along the direction passing through the central axis of the lens body, the normal line of any point on the section line of the sub-composite surface in the section is the same as the normal of the sub-composite surface. The central axis of the lens body intersects below the lens body.

In the utility model, the bottom composite surface of the lens body includes a sub-composite surface, which is annular and generally at an angle protruding toward the top of the lens body, and the Fresnel interface reflected light reflected by the outgoing surface deviates from the The direction of the central axis of the lens body is reflected, which effectively reduces the accumulation of light at small angles in the center caused by the light reflected by the Fresnel interface, increases the intensity of the light field away from the center of the lens, and improves the uniformity of backlighting.

Further, the bottom composite surface includes at least two sub-composite surfaces, and the sub-composite surfaces are connected through non-working surfaces; the sub-composite surfaces and non-working surfaces of the bottom composite surface form a zigzag ring (the bottom composite surface The composite surface crosses the section of the central axis of the lens body, and the section line formed by sectioning is sawtooth; each serration includes the section line of the non-working surface and the adjacent sub-composite surface; overall, the bottom composite The surface forms a ring structure).

As a preference, the angle between the non-working surface and the bottom surface of the lens is between 75° and 90°; the sawtooth ring formed within the above angle range can ensure the effective area of the sub-composite surface to the greatest extent, and it is also convenient Demolding during lens body production.

As a preference, the sawtooth roots of the sawtooth section lines of the bottom composite surface are located on the same straight line, and the design of the sawtooth roots on the same straight line is simple in structure, convenient for processing and manufacturing, and reduces production costs.

As a preference, the root of the sawtooth on the sawtooth section line of the bottom compound surface is located on a curve, which can increase the flexibility of optical and mechanical design and control Fresnel reflected light more effectively.

Provided is a direct-down LED backlight lighting system based on the above-mentioned lens, including an LED light source arranged on a PCB board and the direct-down backlight LED lens installed above the LED light source to realize secondary light distribution.

Further, the system further includes a diffusion plate, and the diffusion plate is arranged in front of the lens. The application of the diffusion plate can further diffuse the light emitted by the LED light source on the PCB to the light-emitting surface better and more uniformly. Such a system can increase the distance between the LED light sources, reduce the number of LEDs, and shorten the distance between the LED light source and the diffuser plate under the premise of the same light output area and the same illuminance uniformity on the diffuser plate, so that The cost of the direct-lit LED backlighting system is reduced and the volume is reduced.

Further, the utility model also includes a TV, including the above-mentioned backlighting system.

Further, a panel light is provided, including the above-mentioned high-order aspect type direct-type LED backlighting light distribution lens.

The utility model has the following beneficial effects: the utility model provides a high-order aspect type direct-type LED backlight light distribution lens; by adjusting the surface shape of the outgoing surface and the incident surface, the light is reasonably distributed, and the uniform illumination is achieved. Under the premise of reliability, the amount of lens used on the LED backlight panel can be reduced, and at the same time, the thickness from the LED light source to the diffusion plate can be reduced, reducing the volume of the system.

Secondly, the bottom surface of the lens body of the utility model includes a bottom composite surface, and the bottom composite surface includes at least one sub-composite surface, and the normal line of any point on the section line of the sub-composite surface along the central axis direction of the lens body is the same as the normal line of the sub-composite surface. The central axis of the lens body intersects below the lens body. The sub-composite surface at the bottom of the lens is ring-shaped, reflecting the Fresnel interface reflected light reflected by the outgoing surface to the direction away from the central axis of the lens body, effectively reducing the noise caused by the Fresnel interface reflected light. The accumulation of small angle rays in the center.

Description of drawings

FIG. 1 is a schematic diagram of a reflective backlight lens system in the prior art.

Fig. 2 is a three-dimensional appearance and a half-section structure diagram of a high-order aspect type direct-type LED backlighting light distribution lens.

Fig. 3 is a partially enlarged schematic diagram of a cross-section of the bottom composite surface of a high-order aspect type direct-type LED backlighting light distribution lens.

4 is a schematic cross-sectional view of the bottom composite surface of the high-order aspect type direct-type LED backlighting light distribution lens.

FIG. 5 is a schematic perspective view of the three-dimensional structure of Embodiment 1.

6 is a schematic cross-sectional view of Embodiment 1.

FIG. 7 is a bottom view of Embodiment 1. FIG.

FIG. 8 is a schematic perspective view of the second embodiment.

9 is a schematic cross-sectional view of Embodiment 2.

Fig. 10 is a bottom view of Embodiment 2.

Detailed ways

The technical scheme of the utility model is described in detail below in conjunction with the accompanying drawings and embodiments.

In order to achieve the above effects, the utility model provides a high-order aspect type direct-type LED backlight light distribution lens, which has such a high-order control surface type lens can effectively control the distribution of forward refracted light, especially large The distribution of angled light can better meet the needs of backlighting. At the same time, a composite surface is set at the bottom of the lens, which can effectively control the distribution of Fresnel reflected light in the illumination light field and reduce the accumulation of outgoing light in the central light field.

In order to realize above-mentioned technical effect, the utility model takes following technical scheme:

In order to solve the above problems, the utility model proposes a high-order aspect type direct-type LED backlighting light distribution lens; as shown in Figure 2, it includes a lens body 300, wherein the lens body 300 includes an exit surface 302, an incident surface 301 and The bottom composite surface 303; the exit surface 302, the incident surface 301 and the bottom composite surface 303 are all coaxial with the lens body 300;

Wherein the outgoing surface 302 is located on the outer surface of the lens body 300, and the bottom of the outgoing surface 300 is connected to the bottom composite surface 303 of the lens body 300 (it may also be connected to the bottom composite surface 303 through the side 304);

The bottom composite surface is located at the bottom of the lens body 303, and the side close to the central axis of the lens body 300 is connected to the incident surface 301;

The incident surface 301 is located at the center of the bottom of the lens body 300 and is concave toward the top of the lens body 300 .

The surface shapes of the outgoing surface 302 and the incident surface 301 of the lens body are high-order curved surfaces. Among them, both the incident surface and the exit surface can be determined by the equation To describe, where c is the curvature of the vertex of the surface, k is the quadratic aspheric coefficient, r is the radial coordinate (r ² =x ² +y ² ), z is the axial coordinate, α _i is the i-term coefficient, and i is 1, 2, 3... natural numbers.

Further, at least one of the coefficients α _i in the terms of the expression i≧6 of the exit surface of the lens described in the present invention is not zero.

Further, at least one coefficient α _i in the terms of the incident surface expression i≥4 of the lens described in the present invention is not zero.

The lens with this high-order term control surface can effectively control the distribution of forward refracted light, especially the distribution of large-angle light, and can better meet the needs of backlighting.

Further, the bottom composite surface 303 includes at least one sub-composite surface 303-1 (as shown in Figure 2, Figure 3 and Figure 4), when the sub-composite 303-1 surface is cut along the direction passing through the central axis of the lens body , the normal FF' of any point on the section line of the sub-composite surface 303-1 in the section intersects the central axis 00' of the lens body below the lens body. (As shown in Figure 4).

Further, the bottom composite surface includes at least two sub-composite surfaces 303-1, and the sub-composite surfaces 303-1 are connected through a non-working surface 303-2; the bottom composite surface 303 passes through the central axis of the lens body The cross-section, the section line formed by cutting is zigzag (as shown in Figure 2, Figure 3 and Figure 4); overall, the bottom composite surface forms a ring structure.

The design of this zigzag annular compound surface further divides the light field of the reflected light on the bottom surface of the lens. The reflected light field of each sub-composite surface forms a sub-reflected light field, which will pass through the Fresnel light reflected from the exit surface. The light reflected from the interface is more uniformly reflected in a direction deviating from the central axis of the lens body, which further improves the uniformity of the large-angle light of the lens, and further improves the light extraction performance of the lens.

This patent further provides a backlight lighting system, including an LED light source arranged on a PCB board and the direct-type backlight LED lens installed above the LED light source to realize secondary light distribution, and the lens is the above-mentioned lens. Such a system can increase the distance between the LED light sources, reduce the number of LEDs, and shorten the distance between the LED light source and the diffusion plate under the premise of the same light emitting area and the same illuminance uniformity, making the direct LED backlight Lighting systems are reduced in cost and size.

Further, the system further includes a diffusion plate, and the diffusion plate is arranged in front of the lens. The application of the diffusion plate can further better and more evenly diffuse the light emitted by the LED light source on the PCB to the light-emitting surface.

Further, the system also includes a reflective layer, which is located in front of the PCB board and closely adheres to the PCB board; although the dependence of the refraction secondary light distribution lens on the reflective layer in the utility model is It is very low, but the use of the reflective layer can better improve the light energy utilization efficiency of the backlight lighting system and achieve a good energy-saving effect.

The utility model also includes a TV, including a backlight lighting system, the backlight lighting system includes an LED light source arranged on the PCB board and the direct-type backlight LED lens installed above the LED light source to realize secondary light distribution, the lens It is the light distribution lens for uniform light direct type LED backlighting described in this patent.

The utility model also includes a panel light, which includes a backlight lighting system, and the backlight lighting system includes a light distribution lens for uniform light direct-down LED backlight lighting described in this patent to realize secondary light distribution.

The utility model is not limited to the aforementioned specific embodiments. The utility model extends to any new feature or any new combination disclosed in this specification, as well as the steps of any new method or process or any new combination disclosed.

Example 1

The exit surface and incident surface of the backlight lens in this embodiment are high-order facets as in the specific implementation, which can better and effectively control the distribution of forward refracted light, especially the distribution of large-angle light, and can better meet The need for backlighting; in addition, the bottom composite surface includes a sub-composite surface, and the normal line of any point on the section of the sub-composite surface intersects with the central axis of the lens body below the lens body, as shown in Figure 5 and Figure 6 And shown in Figure 7 (wherein Figure 5 is a three-dimensional structural schematic diagram of this embodiment; Figure 6 is a schematic cross-sectional view of this embodiment; Figure 7 is a bottom view of this embodiment). The rest of the structure and working principles of this embodiment are the same as those of the above-mentioned specific implementation, and will not be repeated here.

Example 2

The exit surface and incident surface of the backlight lens in this embodiment are high-order facets as in the specific implementation, which can better and effectively control the distribution of forward refracted light, especially the distribution of large-angle light, and can better meet The need for backlighting; in addition, the bottom composite surface of the lens includes 6 sub-composite surfaces, the section line of the bottom composite surface is zigzag, and the sawtooth roots of the section line of the bottom composite surface are located on the same straight line, which is consistent with this implementation For example, the central axis of the lens body is vertical; and the section line of the sub-composite surface is a straight line structure, not only that, the sub-composite surface is arranged in a denser arrangement closer to the edge of the lens body, as shown in Figure 8, Figure 9, As shown in Fig. 10 (wherein Fig. 8 is the three-dimensional structure schematic diagram of the present embodiment; Fig. 9 is the sectional schematic view of the present embodiment; Fig. 10 is the bottom view of the present embodiment), the remaining structures and working principles of the present embodiment are the same as the above-mentioned specific implementation The method is the same and will not be repeated here.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. A high-order aspect type direct-type LED backlighting light distribution lens includes a lens body, wherein the lens body includes an exit surface and an incident surface; it is characterized in that the surface types of the incident surface and the exit surface can be by the equation to describe; where c is the vertex curvature of the surface, k is the quadratic aspheric coefficient, r is the radial coordinate (r ² =x ² +y ² ), z is the axial coordinate, α _i is the i-th term coefficient, i are 1, 2, 3...natural numbers; at least one coefficient α _i in the items of the exit surface expression i≥6 is not zero. 2. A high-order aspect-type direct-type LED backlighting light distribution lens as claimed in claim 1, characterized in that there is at least one coefficient α _i in the items of the incident surface type expression i≥4 is not zero. 3. A high-order aspect type direct type LED backlighting light distribution lens as claimed in claim 1, wherein the lens body further comprises a bottom composite surface, and the bottom composite surface is the same as the lens body. Axis; the bottom composite surface includes at least one sub-composite surface, when the sub-composite surface is cut along the direction of the central axis of the lens body, the normal line of any point on the section line of the sub-composite surface in the section is the same as the normal of the sub-composite surface The central axis of the lens body intersects below the lens body. 4. A high-order aspect type direct-type LED backlighting light distribution lens as claimed in claim 3, wherein said bottom compound surface comprises at least two sub-composite surfaces, and said sub-composite surfaces are passed through The working surface is connected. 5 . The high-order aspect-type direct-type light distribution lens for LED backlighting according to claim 4 , wherein the angle between the non-working surface and the bottom surface of the lens is between 75° and 90°. 6. A high-order aspect-type direct-type LED backlighting light distribution lens as claimed in claim 4, characterized in that, the sawtooth roots of the sawtooth cross-hatching of the bottom compound surface are located on the same straight line, or located on the same straight line. on the curve. 7. A kind of high-order aspect type direct type LED backlighting light distribution lens as claimed in claim 3, is characterized in that, lens has a sub-composite surface, and described sub-composite surface is arranged at the bottom of the lens body and the illuminance from the peak value to the area of 10% peak value; the section line of the sub-composite surface is a straight line or a curve. 8. A backlighting system, comprising an LED light source arranged on a PCB board and a direct backlight LED lens installed above the LED light source to achieve secondary light distribution, characterized in that the lens is one of claims 1 to 7 lens. 9. A TV, comprising a backlighting system, said backlighting system comprising an LED light source arranged on a PCB board and a direct-down backlight LED lens installed above the LED light source to realize secondary light distribution, characterized in that said lens It is the lens described in any one of claims 1-7. 10. A panel light, comprising a backlighting system, said backlighting system comprising a direct-lit backlight LED lens for secondary light distribution, characterized in that said lens is the lens according to any one of claims 1-7.