TWI624619B - Light-emitting device - Google Patents

Abstract

The light emitting device comprises a lamp cover, a light transmissive front cover, a light emitting element, a radiation layer and a reflective layer. The light transmissive front cover is combined with the lamp cover and a cavity is formed therebetween. The illuminating element is disposed on the lamp cover and located within the cavity. The illuminating element is configured to emit light toward the light transmissive front cover. A radiation layer is formed on the lamp cover and a reflective layer is disposed thereon.

Description

Illuminating device

The present invention relates to a light-emitting device, and more particularly to a light-emitting device having a radiation layer.

Conventional light-emitting devices inevitably generate heat while emitting light. The more light-emitting elements, the more heat is generated, which may cause the light-emitting device to fail beyond the thermal load. Therefore, there is a need to propose a new light-emitting device that can improve heat dissipation efficiency.

The present invention relates to a light-emitting device that can ameliorate the aforementioned problems.

According to an embodiment of the invention, a lighting device is proposed. The light emitting device comprises a lamp cover, a light transmissive front cover, a light emitting element, a radiation layer and a reflective layer. The light transmissive front cover is combined with the lamp cover and a cavity is formed therebetween. The illuminating element is disposed on the lamp cover and located in the cavity, and the illuminating element is configured to emit light toward the transparent front cover. A radiation layer is formed on the lamp cover and a reflective layer is disposed thereon.

In order to better understand the above and other aspects of the present invention, the following detailed description of the embodiments and the accompanying drawings

100‧‧‧Lighting device

120‧‧‧shade

110‧‧‧Light front cover

120s1‧‧‧ inner surface

120s2‧‧‧ outer surface

125‧‧‧Circuit board

130‧‧‧Lighting elements

131‧‧‧ lens

140‧‧‧radiation layer

150‧‧‧reflective layer

H1‧‧‧heat

L1‧‧‧Light

R1‧‧‧ cavity

T1, T2, T3‧‧‧ thickness

FIG. 1 is a schematic view of a light emitting device according to an embodiment of the invention.

Fig. 2 is a partial cross-sectional view of the light-emitting device of Fig. 1 taken along the direction 2-2'.

1 and 2, FIG. 1 is a schematic view of a light-emitting device 100 according to an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of the light-emitting device 100 of FIG. 1 along a direction 2-2'.

The illumination device 100 can be applied to street lamps or other products that require illumination. The light emitting device 100 includes a light transmissive front cover 110, a lamp cover 120, a circuit board 125, at least one light emitting element 130, a radiation layer 140, and a reflective layer 150.

The light transmissive front cover 110 is combined with the lamp cover 120 and a cavity R1 is formed therebetween. Although the figure is not shown, the light-transmitting front cover 110 and the lamp cover 120 can be fixed to each other by snapping, locking or bonding, so that the cavity R1 between the light-transmitting front cover 110 and the lamp cover 120 is like a closed space, thereby making the outside world Environmental factors (such as liquids, moisture, impurities, etc.) do not easily enter the cavity R1.

The circuit board 125 is disposed on the lamp cover 120. The light-emitting element 130 is disposed on the circuit board 125 and emits light L1 toward the lens 131 and the light-transmitting front cover 110, wherein the light L1 is, for example, visible light. The lens 131 and the light-transmitting front cover 110 are designed such that the light L1 passes through the lens 131 and the light-transmitting front cover 110 to generate a predetermined illumination area. The circuit board 125, the light-emitting element 130 and the lens 131 are located in the cavity R1 to be protected by the transparent front cover 110 and the lamp cover 120, thereby reducing or avoiding damage from the external environment. The globe 120 is, for example, a die cast. The material of the lamp cover 120 is, for example, a metal such as aluminum or other heat-dissipating material, and the heat H1 generated by the light-emitting element 130 can be quickly convected or radiated into the environment to increase the heat dissipation effect.

The radiation layer 140 is formed on the globe 120. For example, the radiation layer 140 may be formed directly or indirectly by spraying in a portion of the inner surface 120s1 of the globe 120 that is covered by the cavity R1. In another embodiment, the radiation layer 140 may be formed more outside the portion of the inner surface 120s1 of the globe 120 that is covered by the cavity R1, such as the outer surface 120s2 of the globe 120 or the entire inner and outer surfaces of the globe 120.

The radiation layer 140 can conduct the heat H1 in the cavity R1 to the lamp cover 120 to improve the heat dissipation efficiency of the light emitting device 100. In detail, limited by the cavity R1, the light L1 may be cyclically reflected in the cavity R1, causing the heat H1 in the cavity R1 to accumulate, causing the temperature of the light-emitting device 100 to rise, but due to the radiation layer 140 of the embodiment of the present invention. The heat energy generated by the light-emitting element 130 can be quickly transmitted to the lamp cover 120 through the radiation layer 140, and then radiated to the external environment through the lamp cover 120, and the radiant energy is included in the visible light or invisible wavelength range of the light L1, so that the light is emitted. The heat dissipation efficiency of the device 100 is improved. Therefore, the radiation layer 140 of the embodiment of the present invention can be used as a heat conduction layer.

Since the heat dissipation efficiency of the light-emitting device 100 is improved, the light-emitting element 130 can be disposed in the sealed cavity R1 without opening a hole in the lamp cover 120 to improve heat dissipation efficiency, or reduce the gap between the light-transmitting front cover 110 and the lamp cover 120. Adhesion. In detail, although the light L1 emitted from the light-emitting element 130 is inevitably refracted in the cavity R1, due to the design of the radiation layer 140, part of the radiant heat of the light L1 can be quickly transmitted to the lamp cover 120 through the radiation layer 140, and then The radiation is radiated to the external environment through the lamp cover 120, so that the temperature and pressure fluctuation range in the cavity R1 can be reduced, thereby reducing or avoiding the decrease in the adhesion between the light-transmitting front cover 110 and the lamp cover 120, because if the cavity R1 is When the temperature fluctuation range is increased, the pressure fluctuation range is also severe, and the adhesion between the light-transmitting front cover 110 and the lamp cover 120 is inevitably lowered.

In an embodiment, the heat radiation efficiency of the globe 120 is less than the heat radiation efficiency of the radiation layer 140. Since the radiation layer 140 provides a higher heat radiation efficiency, even if the heat radiation efficiency of the globe 120 is low, the overall heat dissipation efficiency of the light-emitting device 100 can be improved only by the radiation layer 140. In one embodiment, the heat radiation efficiency of the radiation layer 140 is greater than 0.9, and the heat radiation efficiency of the globe 120 is about 0.4.

In an embodiment, the total thickness of the thickness T1 of the radiation layer 140 and the thickness T2 of the reflective layer 150 may be between 60 microns and 200 microns. Because the radiation layer 140 of the embodiment of the present invention can quickly transfer the heat H1 to the lamp cover 120, compared with the design of the non-radiation layer 140 and the reflective layer 150, although the thickness T3 of the light-emitting device 100 of the embodiment of the present invention is due to the radiation layer 140 and The reflective layer 150 is increased, but the heat dissipation efficiency of the light-emitting device 100 is instead increased. According to the experiment, the heat dissipation efficiency of the light-emitting device 100 of the embodiment of the present invention is increased by 3%.

Since the light-emitting device 100 of the embodiment of the present invention can effectively improve the heat dissipation efficiency, even if the number of the light-emitting elements 130 is large, the heat dissipation efficiency can be ensured. In an embodiment, the number of light emitting elements 130 is, for example, twelve.

The reflective layer 150 is formed on the radiation layer 140, wherein the radiation layer 140 is located between the reflective layer 150 and the globe 120. The reflective layer 150 reflects the light ray L1 circulating in the cavity R1, thereby improving the light-emitting intensity of the light-emitting device 100. Due to the design of the radiation layer 140, the reflective layer 150 can have a high reflectivity. The high reflectivity reflective layer 150 enhances the recovery efficiency of the light emitted by the light-emitting element 130 in the cavity R1, and reduces the accumulated amount of heat H1 in the cavity R1. However, the design of the radiation layer 140 can still be used. The accumulated heat H1 is quickly conducted to the globe 120 and then radiated or convected through the globe 120 to the outside environment. In an embodiment, the reflective layer 150 may have a reflectivity greater than 85%. In addition, the material of the reflective layer 150 can be Includes titanium oxide or zinc oxide. The weight percentage of titanium oxide or zinc oxide may be between about 0.5% and 15%.

The reflective layer 150 can be formed directly or indirectly on the radiation layer 140, for example, by spraying (e.g., baking varnish). Since the reflective layer 150 and the radiation layer 140 are respectively formed, the radiation layer 140 and the reflective layer 150 have a two-layer different structure with a distinct interface therebetween. In another embodiment, depending on the material and/or process of the reflective layer 150 and the radiation layer 140, the interface between the radiation layer 140 and the reflective layer 150 may also be insignificant or nearly indistinguishable.

In the embodiment of the present invention, the radiation layer 140 and the reflective layer 150 are disposed, so that the light L1 is reflected by the reflective layer 150 and then emitted by the transparent front cover 110, and the generated heat H1 can be transmitted from the radiation layer 140 to the lamp cover 120. The overall optical efficiency of 100 is up to 95%.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (8)

A light-emitting device comprising: a light cover; a light-transmissive front cover coupled to the light cover and forming a cavity therebetween; a light-emitting element disposed on the light cover and located in the cavity, the light emitted by the light-emitting element Light is emitted through the transparent front cover; a radiation layer is formed on the lamp cover; and a reflective layer is formed on the radiation layer; wherein the heat radiation efficiency of the lamp cover is less than the heat radiation efficiency of the radiation layer. The illuminating device of claim 1, wherein the reflective layer has a reflectance greater than 85%. The illuminating device of claim 1, wherein the material of the reflective layer comprises titanium oxide or zinc oxide. The illuminating device of claim 3, wherein the titanium oxide or zinc oxide has a weight percentage of between 0.5% and 15%. The illuminating device of claim 1, wherein the radiation layer and the reflective layer have an interface. The illuminating device of claim 1, wherein the radiant layer and the reflective layer have a different structure. A light-emitting device comprising: a lamp cover; a light-transmitting front cover combined with the lamp cover and forming a cavity therebetween; a light-emitting element disposed on the lamp cover and located in the cavity, the light emitted by the light-emitting element is transmitted through the transparent front cover; a radiation layer is formed on the lamp cover; and a reflective layer is formed on the radiation layer And wherein the sum of the thickness of the radiation layer and the thickness of the reflective layer is between 60 microns and 200 microns. A light-emitting device comprising: a light cover; a light-transmissive front cover coupled to the light cover and forming a cavity therebetween; a light-emitting element disposed on the light cover and located in the cavity, the light emitted by the light-emitting element Light is emitted through the transparent front cover; a radiation layer is formed on the lamp cover; and a reflective layer is formed on the radiation layer; wherein the radiation layer has a heat radiation efficiency greater than 0.9.