WO2015043468A1

WO2015043468A1 - Lens and lighting device comprising same

Info

Publication number: WO2015043468A1
Application number: PCT/CN2014/087274
Authority: WO
Inventors: 邓诗涛; 杨静
Original assignee: 欧普照明股份有限公司
Priority date: 2013-09-29
Filing date: 2014-09-24
Publication date: 2015-04-02
Also published as: CN104515064A; CN104515064B

Abstract

A lens (1) and lighting device comprising the same; the lens (1) has an mounting surface (103), and extends in a direction parallel to the mounting surface (103); the lens (1) comprises a light incident surface (101) forming the inner contour of the lens (1) and a light emergent surface (102) forming the outer contour of the lens (1); the light incident surface (101) and the light emergent surface (102) are connected via the mounting surface (103); the light incident surface (101) is a concave curved surface, and forms a recess accommodating a plurality of light sources; the cross sections of the lens (1) perpendicular to the extending direction are bilaterally symmetrical; the outer contour line of the cross section is a length of an arc line, and the inner contour line is a free curve. The design of the lens enables LED emitted light to change from a Lambert mode light distribution to a light distribution with almost equal light intensity in each direction across 180 degrees. Compared with an existing LED lamp tube, a lamp tube employing the lens of the present invention has a larger light exiting angle and wider applications.

Description

A lens and a lighting device including the same

Technical field

The present invention relates to the field of LED illumination, and more particularly to a lens and an illumination device including the same.

Background technique

Because LED has the advantages of small size, long life, high luminous efficiency, low heat generation, no radiation, low energy consumption and environmental protection and no mercury, it is a green energy-saving and environmentally-friendly lighting product. Governments are actively encouraging the development of LED lighting technology to save energy. Reduce pollution. With the rapid development of LED lighting, existing traditional light source products are gradually being replaced by LED light source products. At present, most of the LED tubes on the market use white LEDs arranged in a row, and then a matte cylindrical diffusion cover is placed on the outside to replace the traditional fluorescent tubes.

However, the difference in light distribution between the fluorescent tube and the LED tube largely limits the development of the LED tube. It can be seen from Fig. 1 that the difference between the fluorescent tube and the LED tube is different. The fluorescent tube is illuminated 360 degrees, and the LED tube has a small illumination angle. In the figure, A is a fluorescent tube, and B and C are LED tubes. . Later, there were some products that increased the angle of light by increasing the degree of diffusion on the surface of the lampshade, but this brought about a problem of reduced light efficiency.

Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a large-angle lens for an LED lamp and an illumination device including the same.

The technical solution of the present invention is to provide a lens having a mounting surface, the lens extending in a direction parallel to the mounting surface, the lens comprising a light incident surface constituting an inner contour of the lens and a light constituting an outer contour of the lens a surface, the light incident surface and the light exit surface are connected by a mounting surface, the lens is vertical The cross section of the extending direction is bilaterally symmetrical, and the light incident surface is a concave curved surface, forming a concave portion, the concave portion can accommodate a plurality of light sources, and the outer contour line of the cross section is a circular arc line, and the inner contour line For the free curve.

Preferably, the free curve of the inner contour line causes the incident angle i and the exit angle γ of the light incident on the light incident surface to satisfy the following equation γ=C3·i3+C2·i2+C1·i+C0, where C3=- 6.4674744E-05, C2=1.8103132E-03, C1=1.2487639, C0=0.16066865.

Preferably, the center of the outer contour arc is below the light source.

Preferably, the surface of the light-emitting surface is sandblasted by matte surface.

The present invention also provides an illumination device comprising the above lens, two or more light sources arranged in a line, and a circuit board carrying the light source, the lens covering the light source.

Preferably, the lens cover has a cover.

Preferably, the mask comprises a phosphor layer or comprises a phosphor.

Preferably, the light source is a blue LED, and the phosphor is a yellow phosphor.

The present invention adopts the above technical solution, and compared with the prior art, the lens design adopted by the present invention makes the light emitted from the LED and the light distribution from the Lambertian type change to a direction of 180 degrees, and the light intensity in each direction is almost Equal light distribution. Compared with the existing LED tube, the lamp tube using the lens has a larger exit angle and a wider application.

DRAWINGS

1 is a diagram showing a difference in light distribution between a fluorescent tube and an LED tube;

Figure 2 is a schematic view showing the structure of the lens of the present invention;

Figure 3 is a cross-sectional view of the lens of the present invention;

Figure 4 is a ray tracing diagram of the lens of the present invention;

Figure 5 is a graph showing the relationship between the incident angle of the lens entrance surface and the exit angle of the lens of the present invention;

Figure 6 is an optical simulation light distribution diagram of a lens of the present invention.

detailed description

The lens and the illumination device including the same according to the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to the specific embodiment shown in FIG. 2 and FIG. 3 , the embodiment is a lighting module for a lamp tube, comprising a lens 1 and an LED light bar 2 , wherein the lens 1 and the LED light bar 2 are mounted on the same plane. The LED strip 2 is covered by the lens 1. In some other embodiments, the lens 1 and the LED light bar 2 may not be mounted on the same plane because of the lens holder or some other mounting manner. For convenience of explanation, what we call the mounting plane refers to the lens 1 and the supporting portion. Contact plane. In the present embodiment, an LED is used as a light source, and the LED herein may refer to a packaged LED, an unpackaged LED, a surface mount LED, a chip-on-board LED, and an LED including a certain type of optical component. The light source of the LED light bar of this embodiment adopts an LED of SMT package, such as 2323, 5630, 3014 and the like.

The lens 1 is a stretch type lens whose cross-sectional shape is as shown in FIG. Since it is a substitute for the conventional fluorescent tube, it is necessary to achieve a large-angle light distribution effect. The lens 1 is a stretch type lens which extends horizontally in one direction parallel to the mounting plane, and has the same cross section perpendicular to the extending direction. 3, the lens 1 includes a light incident surface 101 constituting a lens inner contour and a light exit surface 102 constituting a lens outer contour. The light incident surface 101 and the light exit surface 102 are connected by a mounting surface 103, wherein the light emitting surface 102 is The cross section is a circular arc line to form an outer contour line, and the cross section of the light incident surface 101 is a free curve to form an inner contour line. The light incident surface 101 defines a recessed space that can accommodate a plurality of linearly arranged light sources, that is, the LED light strip 2, with a plane perpendicular to the mounting plane and passing through the optical axis of the LED light strip 2 as a reference surface, and the lens 1 is in the The reference faces are symmetrical in shape.

In order to achieve a large-angle light distribution effect, the following design is adopted in this embodiment, and FIG. 4 is a ray tracing diagram of the lens of the embodiment. As shown in FIG. 3 and FIG. 4, the light emitted by the LED passes through the light incident surface 101 and is once refracted. The angle between the incident light and the optical axis of the LED is i, and the angle between the incident light of the outgoing light and the optical axis of the LED is γ. The optical axis of the LED mentioned here is a virtual one perpendicular to the mounting surface. The straight line, the light incident surface is represented as a free curve on the sectional view, and the free curve satisfies the following equation γ=C3·i3+C2·i2+C1·i+C0, where C3=-6.4674744E-05, C2=1.8103132E -03, C1 = 1.2487639, C0 = 0.166066865. Figure 5 is a plot of the incident angle i and the exit angle γ in the equation. The center of the arc of the outer contour line of the light exiting surface 102 is below the LED light bar 2. In this embodiment, the mounting plane and the LED light bar 2 are in the same plane, that is, the center of the circle is below the mounting plane. The center of the arc is below the LED light-emitting surface, which is more conducive to the deflection of the light toward a large angle. 6 is an optical simulation light distribution diagram of the lens of the embodiment, which is a light distribution curve on two planes, wherein the middle portion resembling an elliptical shape is a plane along the stretching direction of the lens, which is similar to the Lambertian type. Light; as shown in the figure, the butterfly-shaped light distribution map is a plane in which the vertical lens is stretched, and is a large-angle light distribution, and the light intensity is almost equal in each direction in the 180-degree direction.

In addition, we can also optimize the lens shape design, and do some surface treatment (such as matte sandblasting) on the light exit surface 102 of the lens to increase the light exit angle.

The lens in this embodiment is used for assembling into an LED lamp tube. The lamp tube includes a plurality of LED light sources. The LED light sources are arranged in a line on a circuit board. The lens in this embodiment covers the circuit board, as shown in FIG. 2 . As shown, the LED light source 2 is located below the elongated groove in the middle of the lens. As a tube, a cover is also included outside the lens, and the mask is cylindrical in shape, so that the shape and optical characteristics are closer to the conventional fluorescent tube. The mask is a light transmissive material and may be formed of glass, a transparent resin such as polycarbonate, and a transparent ceramic. A diffusing agent or phosphor may be applied to the inner surface of the mask as needed, or a diffusing agent or phosphor may be included in the mask. In one embodiment, remote phosphor technology is employed to address particle sensation and macular problems due to sparse LED layout. The LED light bar light source adopts a blue light chip, and a lens described by the invention is placed on the light source, and a glass or plastic mask is coated on the outside, and the inner wall of the mask is coated with yellow phosphor.

The above description of the preferred embodiments of the present invention is intended to be illustrative and not restrictive It is obvious to the personnel and should be included in the attached rights The scope of the invention defined by the book is within the scope of the invention.

Claims

A lens having a mounting surface, the lens extending in a direction parallel to the mounting surface, the lens comprising a light incident surface constituting an inner contour of the lens and a light emitting surface constituting an outer contour of the lens, the light incident surface and The light-emitting surfaces are connected by the mounting surface, the lens is symmetrical with respect to a cross section perpendicular to the extending direction thereof, and the light-incident surface is a concave curved surface to form a concave portion, and the concave portion can accommodate a plurality of light sources. The outer contour of the cross section is a circular arc line, and the inner contour line is a free curve.
A lens according to claim 1, wherein the free curve of the inner contour line causes the incident angle i and the exit angle γ of the light incident on the light incident surface to satisfy the following equation γ=C3·i3+C2·i2 +C1·i+C0, where C3=-6.4674744E-05, C2=1.8103132E-03, C1=1.2487639, C0=0.16066865.
A lens according to claim 2, wherein a center of said outer contour arc is below said light source.
A lens according to claim 1, wherein said illuminating surface is subjected to matte blasting.
A lighting device, comprising: the lens according to any one of claims 1 to 4, two or more light sources arranged in a line, a circuit board carrying the light source, the lens covering the light source Above.
A lighting device according to claim 5, wherein said lens housing has a cover.
A lighting device according to claim 6, wherein said mask comprises a phosphor layer or comprises a phosphor.
A lighting device according to claim 7, wherein said light source is a blue LED and said phosphor is a yellow phosphor.