1. Field of the Invention
The present invention relates to a street lamp, more particularly, a street lamp with improved emission efficiency.
2. Description of the Related Art
Street lamps are important and necessary emission devices specially when it is dark at night. Taiwan Patent Gazette No. 228287 and entitled “Improved Structure of Street Lamps” talked about the structure of a conventional street lamp. A conventional street lamp includes a base, a transparent plate, a reflecting cover and an upper cover. The base has a fixing portion and an aperture. The fixing portion is used for receiving a light rod, and the aperture is displaced on the bottom of the base. The transparent plate is mounted on the aperture. The reflecting cover is formed as a concave and arc mask in aluminum, and has a lamp holder. The lamp holder is mounted on an end of the reflecting cover towards the fixing portion, and is used for mounting a lamp. The upper cover has a pivot structure and a clamp. The pivot structure is used for combining with the base, and the clamp is used for fixing on the base.
The light from the lamp is partially emitted through the transparent plate directly and downwardly, and the partial light is emitted to the reflecting cover and is then reflected downwardly.
However, a conventional street lamp has the following problems and defects:
1. high power consumption and low color rendering, and low environmental friendliness: A conventional street lamp generally uses a mercury light bulb or high pressure sodium-vapor light bulb to produce light. For a mercury light bulb, the power consumption is about 250 watts at a luminous intensity of 1500 lumen (lm), which is relatively high. In addition, as mercury bulbs contain mercury and so they do not meet the statutory requirements for environmental protection. As for a high pressure sodium-vapor light bulb, it can produce a luminous intensity of 120 lm/w at 400 watts only. Furthermore, the color of the light is close to the color yellow, thus lowering the color rendering. Hence, if an object is placed under a high pressure sodium-vapor street lamp, the true color of the object cannot be correctly shown. For example, policemen will not be able to tell the exact colors of the images shown on their devices if they stand under a high pressure sodium-vapor street lamp.
2. low reflection efficiency and low emission efficiency: The reflecting cover of a conventional street lamp is made of aluminum by punching, and the surface of the aluminum material is rough and the inside of the reflecting cover cannot disseminate any light because it is not optically designed. This may result in low reflectance. A test shows that the reflectance of the reflecting cover of the conventional street lamp is about 0.5, and the emission efficiency of the lamp is reduced.
Based on the above, it is necessary to provide a street lamp that does not have the above problems.
The present invention is a street lamp with improved emission efficiency. The street lamp of the invention includes a base, a transparent plate, a projecting mirror and a cover. The base has a fixing portion, an aperture and a plurality of pillars. The fixing portion is used for receiving a light rod, and the pillars are mounted around the aperture. The transparent plate is mounted on the aperture. The projecting mirror is formed as a concave and arc mask with a waved shape, and has a plurality of extending portions, a reflecting surface and a lamp holder. The extending portions are corresponding to the pillars and are used for fixing on the pillars. The reflecting surface is mounted on the inner concave side and has a plurality of reflecting sections. The lamp holder is mounted on a sidewall of the projecting mirror and is used for mounting a lamp. The cover has a pivot structure and a clamp. The pivot structure is used for combining with the base, and the clamp is used for fixing on the base.
According to the invention, the reflecting surface has gone through a vacuum surface treatment, and the light bulb is a metal halide light bulb. By using a metal halide light bulb that has low power consumption and high luminous intensity, and a reflecting surface of a precise optical design and average light distribution, the street lamp of the present invention can reduce power consumption, improve emission and multi-reflection efficiencies, and increase the average luminous intensity and the entire luminous effect.
The transparent plate 14 is mounted on the aperture 12. The projecting mirror 15 is mounted above the transparent plate 14, and is formed as a concave and arc mask with a waved shape, and has a plurality of extending portions 151, a reflecting surface 154 and a lamp holder 155. The extending portions 151 are corresponding to the pillars 13, and are used for fixing on each of the pillars 13. In the embodiment, each of the extending portions 151 has a through hole 152 for receiving a fixing element 153 to be fixed into the receiving hole 131 of the pillars 13.
According to
The lamp holder 155 is mounted on a sidewall of the projecting mirror 15 and is used for mounting a lamp 16. In the first embodiment, the lamp holder 155 is mounted on a first sidewall of the projecting mirror 15, and the first sidewall is on a short axle direction of the projecting mirror 15. In the embodiment, the lamp 16 is a metal halide lamp with a luminous intensity of 15500 lumen (lm), a power consumption of 150 watts and a color rendering of 90.
The cover 2 has a pivot structure and a clamp. The pivot structure is used for combining with the base 1, and the clamp 22 is used for fixing on the base 1. In the embodiment, the pivot structure includes a pin 21 for combining with the base 1 so that the cover 2 can be opened or closed corresponding to the base 1.
For
Given the above, the present invention has the following advantages and effects:
1. low power consumption: Because the invention uses the metal halide lamp 16 to produce light, the power consumption is about 150 watts with a luminous intensity of 90-100 lm/w. It thus meets the statutory requirement (the average luminous intensity 20 lux). Compared to mercury lamps and high pressure sodium-vapor lamps, the street lamp of the invention consumes less power and the saving power efficiency is about 62%. Furthermore, the street lamp of the present invention meets the requirement for environmental protection.
2. better color rendering and realistic colors: Because the color rendering of the metal halide lamp 16 of the invention is higher than that of high pressure sodium-vapor lamps, the actual colors of the objects under the street lamp of the invention can be better reflected than under a conventional street lamp. When policemen watch the screen of their devices under the street lamp of the invention, they can clearly see the images shown thereon.
3. improved emission efficiency: Because the reflecting surface 154 has a plurality of reflecting sections (multi-reflectors) and has undergone a vacuum surface treatment, the reflecting efficiency and the optical efficiency of the reflecting surface 154 can be improved greatly. A test shows that the reflectance of the reflecting surface 154 is about 0.8, and the optical efficiency is about 60%. Furthermore, the reflecting surface 154 of the invention is made with a precise optical design, and can raise the average and uniformity of the luminous intensity when distributing the light. A test using the present invention along the roadside shows that the average luminous intensity can be above 20 lm.
While several embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by those skilled in the art. The embodiments of the present invention are therefore described in an illustrative, but not restrictive, sense. It is intended that the present invention may not be limited to the illustrated forms, and that all modifications that maintain the spirit and scope of the present invention are within the scope defined in the appended claims.
Number | Date | Country | Kind |
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097211737 | Jul 2008 | TW | national |