CN204254331U - Lighting device - Google Patents

Abstract

The utility model provides a kind of lighting device, comprising: light source; Hold the optical cover of described light source; Wherein, at least part of region of the lateral surface of described optical cover is formed with fresnel structure.Lighting device of the present utility model, by arranging fresnel structure on the lateral surface of optical cover, increases the amount of light of lighting device to its side and rear, thus makes the illumination of lighting device more even, and light distribution angle is larger.

Description

Lighting device

Technical Field

The utility model relates to a lighting device.

Background

In recent years, in the field of lighting, the use of LED lamps has become widespread as substitutes for conventional incandescent lamps. This is because energy saving is promoted by using an LED lamp, which can achieve higher energy conversion efficiency than a conventional incandescent lamp.

The light emitted from the incandescent lamp is uniformly distributed in a substantially spherical shape from the front (the direction opposite to the base) to the rear (the direction of the base), and since the LED has the characteristics of small light emitting area, a light emitting range within a hemisphere, rotational symmetry of light distribution, and the like, a certain strategy must be used to make the spatial distribution of the light emitted from the LED lamp uniform and to expand the light distribution angle of the LED lamp. In particular, the illumination range of the LED needs to be extended to the side and the rear of the light emitting surface of the LED.

Some solutions for expanding the light distribution angle exist in the prior art. For example, as disclosed in patent document JP2011-96594, a light-transmitting cover is covered on a light-emitting module to extend a light distribution angle. Of course, the light-transmissive cover may also be replaced with a cover having a high scattering function to achieve the same or similar object. Further, patent document JP 2010-205553 discloses a scheme of expanding a light distribution angle by providing a material having light diffusibility on a light transmissive cover. Further, JP 2010-40364 discloses a configuration in which a lens is provided to reduce the amount of light emitted forward and increase the amount of light emitted sideways, a light guide member is provided on a side portion of the module, a reflection member is provided on an upper portion of the light guide member, the amount of light incident on the light guide member is increased by the lens, and the amount of light emitted rearward is increased by the reflection member on the upper portion of the light guide member.

However, the solutions in the prior art still have the problems of small light distribution angle and uneven illuminance. For example, as shown in fig. 1, a schematic cross-sectional view of one example of a conventional lighting device is shown. It comprises a light source 1, an optical cover 2, a substrate 3, a support 4 and a circuit board 5. In this example, the surface of the top of the optical cover 2 is provided as a concave surface and the inner surface thereof is provided as an arc-shaped surface, so that the effect of reducing light emission to the front of the lighting device and increasing light emission to the side is achieved. Fig. 2 shows a light distribution curve of the lighting device shown in fig. 1. It can be seen that although the light distribution scheme in the prior art is used, the brightness of the emergent light of the lighting device is not uniform, the light intensity in the range of 30-60 degrees is large, and the light intensity at other angles is obviously small.

SUMMERY OF THE UTILITY MODEL

In order to further improve the inhomogeneous problem of luminance of lighting device's the emergent light, the utility model provides a lighting device, include: a light source; an optical housing containing the light source; wherein, at least partial region of the outer side surface of the optical cover is provided with a Fresnel structure.

Further, at least part of the light emitted by the light source is emitted towards the top of the optical cover.

Further, the Fresnel structure is a plurality of Fresnel rings formed by a plurality of edge teeth circumferentially surrounding the outer side surface of the optical cover.

Preferably, the fresnel structure is located on an upper portion of the outer side of the optical cover.

Preferably, the number of the edge teeth is 6-10, and the height of the highest edge tooth in the plurality of edge teeth is 0.65-1.5 mm.

Preferably, the optical enclosure is a lens.

Preferably, the light source is an LED light source.

Preferably, a gap between the optical cover and the light source is filled with a transparent filling material, and the transparent filling material is transparent epoxy resin or transparent silica gel.

The utility model discloses a lighting device through set up the Fresnel structure on the lateral surface at the optics cover, increases the light yield of lighting device to its side and rear to make lighting device's illuminance more even, the grading angle is bigger.

Drawings

FIG. 1 is a schematic cross-sectional view of one example of a prior art lighting device;

FIG. 2 is a light distribution graph of the lighting device shown in FIG. 1;

fig. 3 is a front view of a first embodiment of the lighting device of the present invention;

fig. 4 is a perspective view of a second embodiment of the lighting device of the present invention;

FIG. 5 is a front view of the lighting device shown in FIG. 4;

FIG. 6 is a schematic cross-sectional view of the lighting device shown in FIG. 4;

FIG. 7 is a light distribution graph of the lighting device shown in FIG. 4;

fig. 8 is a schematic cross-sectional view of a third embodiment of the lighting device of the present invention;

fig. 9 is a schematic cross-sectional view of a fourth embodiment of the lighting device of the present invention;

figure 10 is a schematic view of a fresnel structure and its refraction principle.

Description of reference numerals:

1: light sources 2, 2': optical cover

3: substrate 4: support piece

5: circuit board 6: lens and lens assembly

20: the Fresnel structure 200: fresnel ring

Detailed Description

The lighting device of the present invention will be described in further detail with reference to the accompanying drawings and the following detailed description, but the invention is not limited thereto.

First embodiment

Fig. 3 is a schematic view of a first embodiment of the lighting device of the present invention. In this embodiment, the lighting device comprises a light source (not shown in the figures) and an optical cover 2 accommodating the light source, wherein a fresnel structure 20 is formed in at least a partial region of an outer side surface of the optical cover 2. The outer side of the optical cover 2 refers to the outer surface of the side wall thereof. In order to better enlarge the light distribution angle of the lighting device, at least part of light emitted by the light source is preferably emitted towards the top of the optical cover 2, and the Fresnel structure 20 is positioned at the upper part of the outer side surface of the optical cover 2. It can be understood that if the light emitting surface of the light source faces the side surface of the optical cover 2, the light intensity of the side surface of the lighting device is larger at this time, and the fresnel structure 20 may be disposed on the top of the optical cover 2 for uniform light distribution.

Figure 10 is a schematic view of a fresnel structure and its refraction principle. It can be seen that the prism teeth in the fresnel structure can perform the same refraction function as the conventional spherical lens, for example, the prism teeth at the upper part of the fresnel structure shown in fig. 10 can refract light downward, and the prism teeth at the lower part can refract light upward, thereby achieving the same optical effect as the conventional spherical lens. Preferably, the fresnel structure 20 in the lighting device of the present invention is a plurality of fresnel rings 200 formed by a plurality of teeth circumferentially surrounding the outer surface of the optical cover.

When the fresnel structure is applied to the lighting device according to the present invention, referring to fig. 3, the ridge teeth on the upper portion of the fresnel structure 20 (i.e. near the top of the optical cover 2) refract the light downward, so as to change the light path of the light emitted to the front of the lighting device and make the light emitted to the side or the rear of the lighting device; meanwhile, the prism teeth at the lower part of the fresnel structure 20 (i.e. the top part far from the optical cover 2) refract the light upwards, and the light paths of at least part of the light emitted to the back and the side back of the lighting device originally are changed, so that the light with large angles is converged towards the side of the lighting device, and the illumination intensity at the side is increased. Therefore, the utility model discloses a lighting device is through setting up fresnel structure 20 on the lateral surface at optics cover 2 to the light yield of lighting device to its side and rear has been increased, makes lighting device's illuminance more even, and the grading angle is bigger.

Second embodiment

In order to achieve the desired light extraction effect of the lighting device, the fresnel structure 20 provided on the outer side of the optical cover 2 may be designed as desired. For example, the size, shape, and number of each ridge in the fresnel structure can be changed to change the refraction angle of light, thereby achieving the desired light extraction effect and illumination distribution. Referring to fig. 4-6, it can be seen that in this embodiment, the teeth in the fresnel structure 20 are significantly smaller in height than the teeth in the fresnel structure 20 of the first embodiment, and their shape is also altered. Preferably, the number of teeth of the Fresnel structure 20 is 6 to 10. Since the height of the teeth in the Fresnel structure 20 gradually decreases from the middle to both sides of the Fresnel structure 20, it is preferable that the height of the highest teeth in the Fresnel structure 20 is 0.65 to 1.5 mm.

Fig. 7 is a light distribution graph of the lighting device in this embodiment. Comparing it with the light distribution curve diagram of the lighting device of the prior art in fig. 2, under the same other conditions (for example, the characteristics of the optical cover 2), the light distribution of the lighting device of the present invention is more uniform, and the light distribution angle thereof is more enlarged.

Third embodiment

In the above two embodiments, the optical cover 2 also functions as a lens, i.e., functions as both light guiding and light distributing, while accommodating the light source 1. Therefore, in the above two embodiments, the fresnel structure 20 may also be considered to be disposed on the outer side surface of the lens (the optical cover serving as the lens).

It will be appreciated that the lighting device may include an additional lens 6, separate from the optical cover, to achieve the light guiding and distributing effect. In this configuration, the fresnel structure 20 in the lighting device of the present invention may be provided on the optical cover 2' that does not serve as the lens 6. Fig. 8 shows a third embodiment of the present invention. In this embodiment, the lighting device includes a light source 1, an optical cover 2', a substrate 3, a support 4, a circuit board 5, and a lens 6. A fresnel structure 20 is provided on the outer side of the optical cover 2. The lighting device can also achieve the effects of increasing the light distribution angle and enabling the illumination to be uniform.

Fourth embodiment

In order to improve the light extraction rate of the lighting device, it is preferable that a gap between the optical cover 2 and the light source 1 is filled with a transparent filling material, for example, a transparent epoxy resin, a transparent silicone gel, or the like. Through the application of the filling material, air does not exist between the optical cover 2 and the light source 1, so that the probability of total reflection of light emitted from the light source 1 on a light-emitting surface is greatly reduced, and the light extraction rate of the lighting device is improved. Meanwhile, air does not exist in the lighting device, and adverse consequences that moisture condensation in the air affects lighting and causes short circuit and the like are avoided.

Fig. 9 shows a fourth embodiment of the present invention, which can achieve the same effect as filling the transparent filling material. The optical cover 2 is made into a shape matched with an object contained in an inner cavity of the optical cover, so that the optical cover 2 is tightly connected with the light source 1, the substrate 3, the support piece 4 and the like, the light extraction rate can be improved under the condition that transparent materials are not filled, and adverse effects such as condensation and short circuit are avoided.

Although the fresnel structure 20 shown in the drawings is a fresnel structure of a converging lens, it is understood that the fresnel structure provided in the lighting device of the present invention can be a fresnel structure of a converging lens or a diverging lens.

Meanwhile, the light source type of the lighting device of the present invention is not limited to the LED light source, and may be other light sources such as an incandescent light source and a fluorescent light source.

The shape of the lighting device of the present invention is not limited to the shape shown in the drawings, and may be other shapes.

The above embodiments are only exemplary embodiments of the present invention, and should not be used to limit the present invention, the scope of the present invention is defined by the appended claims. Various modifications and equivalents of the invention can be made by those skilled in the art within the spirit and scope of the invention, and these modifications and equivalents should also be considered as falling within the scope of the invention.

Claims (10)

1. An illumination device, comprising:

a light source;

an optical housing containing the light source; wherein,

at least partial region of the outer side surface of the optical cover is formed with a Fresnel structure.

2. A lighting device as recited in claim 1, wherein at least a portion of light emitted by said light source is directed toward the top of said optical enclosure.

3. A lighting device as recited in claim 1, wherein the fresnel structure is a plurality of fresnel rings formed by a plurality of teeth circumferentially surrounding the outer side of the optical cover.

4. A lighting device as recited in claim 1, wherein the fresnel structure is located on an upper portion of the outer side of the optical cover.

5. A lighting device as recited in claim 3, wherein said number of said teeth is from 6 to 10.

6. A lighting device as recited in claim 3, wherein a height of a highest of said plurality of tines is between 0.65 and 1.5 mm.

7. A lighting device as recited in claim 1, wherein said optical enclosure is a lens.

8. A lighting device as recited in claim 1, wherein said light source is an LED light source.

9. The illumination device of claim 1, wherein a gap between the optical cover and the light source is filled with a transparent filling material.

10. A lighting device as recited in claim 9, wherein said transparent filler material is a transparent epoxy or a transparent silicone.