CN204477931U - A kind of direct-light type LED backlight illumination light-distribution lens, system and a kind of TV - Google Patents

Abstract

The utility model relates to the technical field of backlighting, in particular to a direct-type LED backlighting light distribution lens, a system and a TV. Comprising a lens body, the lens body includes an incident surface, an exit surface, and a bottom composite surface, and the bottom composite surface includes at least two sub-composite surfaces, and the sub-composite surfaces are cut at any point along the section line along the central axis of the lens body The normal line intersects the central axis of the lens body below the lens body; the sub-composite surfaces are connected by a non-working surface; the sub-composite surface and the non-working surface of the bottom composite surface form a zigzag ring; The sub-composite surface reflects part of the Fresnel interface reflected light reflected by the exit surface to the direction away from the central axis of the lens body, reducing the accumulation of light in the central area above the lens; The compound surface design saves space, solves the problem of sub-composite surface setting in a small space, and compresses the lens structure.

Description

Light distribution lens, system and TV for direct-down LED backlighting

technical field

The utility model relates to the technical field of backlighting, in particular to a direct-type LED backlighting light distribution lens, a system and a TV.

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.

An important reason is that when light propagates in different media, there will always be Fresnel interface reflection when the light passes through the interface, and the larger the incident angle is, the more obvious the Fresnel interface reflection effect is. Usually, when propagating from an optically rarer medium to an optically denser medium, the reflectivity of the Fresnel interface will increase with the increase of the incident angle when the incident angle is greater than 60°; The reflection is more significant, and when the incident angle is greater than 30°, the reflectivity of the Fresnel interface will rise sharply with the increase of the incident angle.

The light emitted from the LED light source enters the lens body after being refracted by the incident surface. When it reaches the exit surface, part of the light is refracted through the exit surface, and the other part of the light is reflected by the interface into the lens. This part of the reflected light passes through the bottom of the lens or the inner cavity of the system. After multiple reflections and refractions on multiple surfaces such as the reflective surface, light (energy) concentration will be formed in the middle area above the LED, which seriously affects the uniformity of the light field emitted by the lens.

Referring to FIG. 2 , the light 231 emitted by the LED light source 210 below the incident surface and entering the lens 220 will be separated when reaching the exit surface 223 , and become a refracted ray 232 and a Fresnel reflected ray 233 . Usually, the refracted light 232 will carry most of the energy directly to the diffuser 250, while the Fresnel reflected light 233 will carry a small amount of energy and reflect back to the inside of the lens, and then be reflected by the bottom 222 of the lens body or objects under the bottom of the lens body to form The secondary reflected light 234 , when the secondary reflected light 234 hits the outgoing surface 223 again, is refracted out of the lens to become a light 235 , and the light 235 travels for a certain distance and reaches the diffusion plate 250 . It can be seen from the traveling route of the light that the light 235 will gather in the middle part above the LED 210 . Since the light 231 enters the light-dense medium from the light-dense medium when it reaches the exit surface 223, the reflection effect of the Fresnel interface is relatively obvious, and there is a high reflectivity. The phenomenon of light (energy) accumulation in some areas is more significant, which ultimately affects the uniformity of backlighting.

At the same time, the volume of the backlight lens in the prior art is often small, and it is difficult to reflect the light reflected by the Fresnel interface in a direction deviating from the central axis of the lens body in a limited bottom space, which is structurally difficult to realize.

Utility model content

In order to solve the above problems, the utility model provides a direct-type LED backlight light distribution lens, which can reduce the accumulation of outgoing light in the central light field caused by Fresnel interface reflection in the limited space of the lens, and distribute it reasonably The emitted light can reduce the number of LED light sources used on the LED backlight panel under the premise of achieving the same lighting effect, and at the same time reduce the thickness from the LED light source to the diffuser plate and reduce 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 direct type LED backlight light distribution lens, including a lens body, wherein the lens body includes an exit surface, an incident surface and a bottom compound surface;

The bottom composite surface is located at the bottom of the lens body, and the side close to the central axis of the lens body is connected to the incident surface; the incident surface is located at the bottom center of the lens body and is concave toward the top of the lens body;

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, when the sub-composite When the 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 intersects the central axis of the lens body below the lens body;

The section line length of the sub-composite surface is greater than the section line length of the adjacent non-working surface.

Due to the angle of the sub-composite surface, the Fresnel interface reflected light reflected by the exit surface is reflected away from the central axis of the lens body, which effectively reduces the area above the light source caused by the Fresnel interface reflected light. The accumulation of light increases the intensity of the light field away from the center of the lens and improves the uniformity of the outgoing light field. Moreover, when the bottom sub-composite surface crosses the section of the central axis of the lens body, the section line formed by sectioning is zigzag. This zigzag structure can save space and can be better solved in a small bottom space. The problem of setting the sub-composite surface, reducing the thickness of the lens, compressing the volume of the lens, has achieved the technical effect of reflecting the light reflected by the Fresnel interface in a direction away from the central axis of the lens body.

As a preference, the angle between the non-working surface and the bottom surface of the lens is between 70° 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.

Further, the roots of the sawtooth on the sawtooth line of the bottom compound surface are located in the same plane, and the straight line is perpendicular to the central axis of the lens body; that is, the roots of the sub-composite surfaces of the bottom compound surface of the lens body are located on the same plane at the bottom of the lens body Inside, such a structural design is simple in structure.

As a preference, when the bottom composite surface is cut along the direction passing through the central axis of the lens body, the serration roots on the zigzag section line of the sub-composite surface are located on the same straight line, which is parallel to the central axis of the lens body. inclined, and the normal line of the straight line intersects the central axis of the lens body below the bottom of the lens body, so that it is equivalent to placing all the sawtooth surfaces on a large inclined surface, which can better realize the process from The Fresnel interface reflection light reflected from the exit surface is reflected in a direction away from the central axis of the lens body.

As a preference, when the bottom composite surface is cut along the direction passing through the central axis of the lens body, the sawtooth roots on the jagged section line of the sub-composite surface are located on the curve, so that the sub-composite surface can be designed more flexibly, so that the lens can achieve Better lighting effects.

Further, the section line of the sub-composite surface is a straight line; the conical sub-composite surface has a simple design and structure, which is convenient for processing and manufacturing, and reduces the production cost.

Further, the section line of the sub-composite surface is a curve, and the sub-composite surface is designed as a curved surface, so that the sub-composite surface can be designed more flexibly, so that the lens can achieve a better light distribution effect.

Further, the inclination angle of the sub-composite surface and the bottom surface of the lens body is the same; the same inclination angle facilitates processing and production and reduces production costs.

As a preference, the included angle between the sub-composite surface and the bottom surface of the lens body increases sequentially in a direction closer to the central axis of the lens body. This design with successively decreasing inclination angles can better reflect the light near the concentrated area of Fresnel reflection in the center of the lens body in a direction farther away from the central axis of the lens body, which is conducive to further reducing the accumulation of light near the central axis of the lens . Can achieve better uniform light effect.

Further, the section lines of each sub-composite surface are equal in length, and are uniformly distributed on the bottom composite surface of the lens body; the uniformly distributed sub-composite surface design has a simple structure, is convenient for processing and manufacturing, and is beneficial to Reduce production costs.

As a preference, the lengths of the section lines of the sub-composite surfaces increase sequentially along the direction toward the central axis of the lens body. The distribution near the center of the lens body is sparser, and the distribution near the edge of the lens body is denser; this design of the outer dense reflection ring can reduce the non-working surface near the outer side of the lens adjacent to the inner side of the lens The interference of light reflected by the sub-composite surfaces of .

Further, when the lens is used, the light-emitting surface of the LED is flush with or higher than the bottom surface of the incident surface. In this way, all the light emitted by the light source used in the lens enters the lens body after being refracted by the incident surface, reducing light loss or interference caused by light entering the lens body from other surfaces, and improving the light energy utilization rate of the light source.

As a preference, in order to further improve the uniformity of the outgoing light field, the sub-composite surface is set as a matte surface. In this way, the main direction of the light reflected by the sub-composite surface does not change, and it is still reflected in a direction away from the central axis of the lens body, but the uniformity of the reflected light is further improved, which is conducive to improving the reflection of the sub-composite surface. The phenomenon of uneven distribution of light on the diffuser plate caused by regular secondary reflections.

This patent further provides a system, including an LED light source arranged on a PCB and a lens installed above the LED light source to realize secondary light distribution, and the lens is the above-mentioned light distribution lens for direct LED backlighting. 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.

This patent also provides a TV, including the above system.

The utility model has the following beneficial effects:

The bottom surface of the lens body of the direct-type secondary light distribution lens in the present invention includes a bottom composite surface, and the bottom composite surface includes at least two sub-composite surfaces, and the sub-composite surfaces are connected by non-working surfaces; The section line of the bottom composite surface is zigzag; the normal of any point on the section line of the sub-composite surface along the central axis of the lens body intersects the central axis of the lens body below the lens body. Reflect the light reflected by the Fresnel interface on the exit surface in a direction that deviates from the central axis of the lens body, effectively reducing the accumulation of small-angle light rays at the top center of the lens body caused by the reflected light from the Fresnel interface, and increasing the deviation from the lens body. The light intensity of the light field in the center; at the same time, the sawtooth structure of the light distribution lens for direct-type LED backlighting can save space, and can solve the problem of sub-composite surface setting in a small bottom space, reducing the The thickness of the lens compresses the volume of the lens, and the technical effect of reflecting the light reflected by the Fresnel interface toward the direction away from the central axis of the lens body is well realized; the same illuminance is achieved in the same light output area and on the diffuser plate On the premise of uniformity, increase the distance between LED light sources, reduce the number of LEDs, and shorten the distance between the LED light source and the diffusion plate, so that the cost of the direct LED backlight lighting system is reduced and the volume is reduced.

Description of drawings

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

Fig. 2 is a system schematic diagram of a refractive backlight lens in the prior art.

Fig. 3 is a three-dimensional appearance and a half-section structure diagram of the light distribution lens for direct-lit LED backlighting of the present invention.

FIG. 4 is an enlarged schematic view of a part of the cross-section of the bottom composite surface in FIG. 3 .

Fig. 5 is a schematic cross-sectional view of the bottom composite surface of the new direct type LED backlighting light distribution lens.

FIG. 6 is a schematic perspective view of the three-dimensional structure of Embodiment 1. FIG.

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

FIG. 8 is a bottom view of Embodiment 1. FIG.

FIG. 9 is a schematic diagram of the three-dimensional structure of Embodiment 2.

FIG. 10 is a schematic cross-sectional 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.

The utility model adopts the following technical solutions: the utility model provides a direct-type LED backlighting light distribution lens, which can reduce the accumulation of reflected light at the Fresnel interface in the central area of the lighting light field, and improve the uniformity of the outgoing light field. On the premise of achieving the same illumination uniformity, the number of light sources 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.

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 direct type LED backlighting light distribution lens, as shown in Figure 3, including a lens body 300, wherein the lens body 300 includes an exit surface 302, an incident surface 301 and a 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 outgoing surface 302 , the incident surface 301 and the bottom composite surface 303 are all axisymmetric shapes formed by the corresponding generatrix rotating around the central axis of the lens body 300 . (The enlarged schematic diagram of part A of the bottom composite surface 303 is shown in FIG. 4 )

Further, the bottom composite surface 303 includes at least two sub-composite surfaces 303-1, the sub-composite surfaces 303-1 are along the section passing through the central axis of the lens body, and the normal line of any point on the section line FF' intersects the central axis OO' of the lens body below the lens body (as shown in FIG. 5 ).

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 section lines formed by sectioning are jagged (as shown in Figure 3, Figure 4 and Figure 5); each sawtooth contains the section lines of the non-working surface and the adjacent sub-composite surface; this sawtooth structure , can save space, can solve the problem of sub-composite surface setting in a small bottom space, reduce the thickness of the lens, compress the volume of the lens, and realize the reflection of the Fresnel interface light toward the The technical effect reflected in the direction deviated from the central axis of the lens body.

In addition, further cooperate with the LED light-emitting surface to be flush with the bottom of the incident surface or higher than the bottom of the incident surface, so that all the light emitted by the light source used in this lens can enter the lens body after being refracted by the incident surface, reducing the loss of light or light The crosstalk caused by entering the lens body from other surfaces improves the utilization rate of light energy of the light source.

As a preference, the angle between the non-working surface 303-2 and the bottom surface of the lens (as shown by the number 303-3 in Figure 4) is between 70° and 90°; the sawtooth ring formed within the above angle range can be the largest The effective area of the sub-composite surface is ensured to the greatest extent, and it also facilitates the demoulding during the production process of the lens body.

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.

Further, the roots of the sawtooth on the sawtooth line of the bottom compound surface are located in the same plane, and the straight line is perpendicular to the central axis of the lens body; that is, the roots of the sub-composite surfaces of the bottom compound surface of the lens body are located on the same plane at the bottom of the lens body Inside, such a structural design is simple in structure.

As a preference, when the bottom composite surface is cut along the direction passing through the central axis of the lens body, the serration roots on the zigzag section line of the sub-composite surface are located on the same straight line, which is parallel to the central axis of the lens body. Inclined, and intersect with the central axis of the lens body below the bottom of the lens body, in this way, it is equivalent to placing all the sawtooth surfaces on a large inclined surface, which can better realize the reflection from the exit surface The Fresnel interface reflects the effect of light reflected in a direction away from the central axis of the lens body.

As a preference, when the bottom composite surface is cut along the direction passing through the central axis of the lens body, the sawtooth roots on the jagged section line of the sub-composite surface are located on the curve, so that the sub-composite surface can be designed more flexibly, so that the lens can achieve Better lighting effect.

Further, the section line of the sub-composite surface is a straight line; the conical sub-composite surface has a simple design and structure, which is convenient for processing and manufacturing, and reduces the production cost.

Further, the section line of the sub-composite surface is a curve, and the sub-composite surface is designed as a curved surface, so that the sub-composite surface can be designed more flexibly, so that the lens can achieve a better light distribution effect.

Further, the inclination angle of the sub-composite surface and the bottom surface of the lens body is the same; the same inclination angle facilitates processing and production and reduces production costs.

As a preference, the included angle between the sub-composite surface and the bottom surface of the lens body increases sequentially in a direction closer to the central axis of the lens body. This design with successively decreasing inclination angles can better reflect the light near the concentrated area of Fresnel reflection in the center of the lens body in a direction farther away from the central axis of the lens body, which is conducive to further reducing the accumulation of light near the central axis of the lens . Can achieve better uniform light effect.

Further, the section lines of each sub-composite surface are equal in length, and are uniformly distributed on the bottom composite surface of the lens body; the uniformly distributed sub-composite surface design has a simple structure, is convenient for processing and manufacturing, and is beneficial to Reduce production costs.

As a preference, the lengths of the section lines of the sub-composite surfaces increase sequentially along the direction toward the central axis of the lens body. The distribution near the center of the lens body is sparser, and the distribution near the edge of the lens body is denser; this design of the outer dense reflection ring can reduce the non-working surface near the outer side of the lens adjacent to the inner side of the lens The interference of light reflected by the sub-composite surfaces of .

As a preference, in order to further improve the uniformity of the outgoing light field, the sub-composite surface is set as a matte surface. In this way, the main direction of the light reflected by the sub-composite surface does not change, and it is still reflected in a direction away from the central axis of the lens body, but the uniformity of the reflected light is further improved, which is conducive to improving the reflection of the sub-composite surface. The inhomogeneity on the diffuser plate caused by the regular secondary reflection of Fresnel reflected light.

Further, in order to ensure accurate installation of the lens and the LED light source and convenient assembly of the light distribution lens, positioning devices are provided on the bottom and side surfaces of the lens.

Further, in order to achieve accurate positioning of the installation of the lens and the LED light source panel, improve installation efficiency, and simplify the installation process, a corresponding positioning device matching the positioning device is provided at the corresponding position of the lens corresponding to the LED panel or PCB board.

Further, the positioning device is arranged at the edge position of the bottom of the lens, which may be directly provided at the bottom edge of the lens body, or at a position where the positioning device is specially provided outside the bottom of the lens body.

Further, the positioning device of the lens body is integrally formed with the lens body.

This patent further provides a system, including an LED light source arranged on a PCB and a lens installed above the LED light source to realize secondary light distribution, and the lens is the above-mentioned light distribution lens for direct LED backlighting. 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 output 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 provides a television, including the above-mentioned system.

The utility model also includes a panel light, including the above-mentioned system.

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 bottom composite surface included in the backlight lens in this embodiment includes 6 sub-composite surfaces, the section line of the bottom composite surface is zigzag, and the zigzag root of the section line of the bottom composite surface is located on the same straight line, which is the same as this line. The central axis of the lens body described in the embodiment 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 6 and Figure 7 , shown in Figure 8 (wherein Figure 6 is a schematic diagram of a three-dimensional structure of this embodiment; Figure 7 is a schematic cross-sectional view of this embodiment; Figure 8 is a bottom view of this embodiment), the remaining structures and working principles of this embodiment are the same as those described above The implementation is the same, and will not be repeated here.

Example 2

The bottom composite surface included in the backlight lens in this embodiment includes 6 sub-composite surfaces, the section line of the bottom composite surface is zigzag, and the zigzag root of the section line of the bottom composite surface is located on a curve, any point on the curve The closer to the central axis of the lens body, the greater the distance from the bottom surface of the lens; and the section line of the sub-composite surface is a straight line structure, and not only that, the arrangement of the sub-composite surfaces is denser as it is closer to the edge of the lens body, as shown in Figure 9 As shown in FIG. 10 (wherein FIG. 9 is a schematic perspective view of this embodiment, and FIG. 10 is a schematic cross-sectional view of this embodiment), the rest of the structure and working principle of this embodiment are the same as the above-mentioned specific implementation, 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 direct-light type LED backlight illumination light-distribution lens, comprises lens body, and wherein said lens body comprises exit facet, the plane of incidence and bottom composite surface; Described bottom composite surface is positioned at the bottom of described lens body, is connected with the described plane of incidence near the side of lens body central shaft; The described plane of incidence is positioned at the bottom centre of described lens body, caves in lens body top-direction; It is characterized in that:

Described bottom composite surface comprises at least two sub-composite surfaces, is connected between described sub-composite surface by non-working surface;

The sub-composite surface of described bottom composite surface and non-working surface form zigzag endless belt;

When described sub-composite surface is cut open along the central axis direction of scioptics body, on the hatching of sub-composite surface, the central shaft of the normal of any point in section and described lens body intersects at the below of lens body;

The hatching length of described sub-composite surface is greater than the hatching length of the non-working surface be adjacent.

2. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1, it is characterized in that, the angle of described non-working surface and lens base is between 70 ° to 90 °.

3. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1 or 2, it is characterized in that, the sawtooth root of the hatching of described bottom composite surface is positioned on the same line.

4. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1 or 2, it is characterized in that, the hatching of described sub-composite surface is straight line or curve.

5. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1 or 2, it is characterized in that, described sub-composite surface is identical with the angle of described lens body bottom surface, or increases gradually along the direction near lens centre axle.

6. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1 or 2, it is characterized in that, the length of the hatching of described each sub-composite surface is equal, or increases successively along the direction to lens body central shaft.

7. the direct-light type LED backlight illumination light-distribution lens as described in one of claim 1 or 2, is characterized in that, described sub-composite surface is hair side.

8. direct-light type LED backlight illumination light-distribution lens as claimed in claim 1 or 2, is characterized in that, during described lens use, the exiting surface of LED flushes or higher than the bottom surface of the plane of incidence.

9. a direct-light type LED backlight illumination system, comprise the LED light source that is arranged on pcb board and be arranged on above LED light source to realize the lens of secondary light-distribution, it is characterized in that, described lens are the direct-light type LED backlight illumination light-distribution lens described in one of claim 1 to 8.

10. a TV, is characterized in that, comprises system as claimed in claim 9.