Real interpretation of LED (I)

Although LED (light-emitting diode) more and more into the people's daily lives, but there are still many people on the advantages and disadvantages of LED (yes, it also has shortcomings! Is not very understanding. The following is a real interpretation of the advantages and disadvantages of LED, hoping to allow users to have a comprehensive understanding of the purchase of related products can be more clearly understood.

When people decide to buy LED lamps, they take into account some of the characteristics of the product that the manufacturer has told us: for example, energy saving, cost reduction, long service life, no heat, etc.. Are these real? LED really have such a high energy efficiency? LED light source in the end what are the advantages? Where do they fit in and are not suitable for installation? In order to answer these questions, let us first make a comprehensive understanding of the real advantages of LED.

Solid state lighting (SSL) in the purchase, installation, use and replacement of lamps have the advantages of the process, we have become a new wave or a new generation of lighting technology. SSL is generally considered to be safer, environmentally friendly, longer life, more flexible, high energy efficiency and low cost consumption. As for LED remarkable advantage: hand countable color selection range, and can provide three small size, so it can be embedded in the small space of electrical appliances, and thus to the design provides greater flexibility and portability; low energy consumption. These characteristics are the focus of the manufacturers repeatedly stressed, but they rarely say what exactly the advantages of LED.

The well-known LED manufacturers, such as competition between CREE, Lumileds, Toyoda, Nichia Gosei, GM, OSRAM and other manufacturers, the LED technology has been improved. One thing is certain: LED and LED lighting is gradually replacing traditional lighting (including high intensity discharge lamp, fluorescent lamp and incandescent light source), the new high-performance LED (light-emitting diode) is moving forward.

Solid state lighting: a new generation of lighting

Solid state lighting is now in its earliest stages, and it is considered to be more energy-efficient than incandescent and fluorescent lamps. The energy efficiency is not related to the efficiency of the lumen / watt, but the visual spectrum produced by SSL, and how much of it can be converted directly or indirectly to the available resources. Fluorescent lamps and lanterns can not directly produce the available light, but the lamp tube inside the ionized gas to produce ultraviolet light, ultraviolet light and then through the inner layer of the phosphor coated tube into a visible light, phosphorus can absorb ultraviolet light.

Incandescent, on the other hand, generates a lot of the energy needed to produce heat, and only about 5% of the energy is released into the light we can see. LED converts 25 - 35% of the energy into light and the rest is heat. So LED will also produce heat, but it is the same as the spectrum of the visible part of the spectrum, experts call it "cold light" of the light.

For LED manufacturers, the biggest challenge is the energy efficiency of LEDs and traditional lamps. From this point of view, the most needed is white, and white LED is only recently developed. The question is whether the white LED can be made into a bright and bright white light, at the same time the natural appearance and economy. So far, there is no such a par LED lighting products, because manufacturers have not overcome a very important issue: lumen value. Traditional incandescent bulbs cost about $1 per thousand lumens, while LED costs $200 or more.

If we use lm/W to measure the performance of the product, we will find that there are still some shortcomings in LED, and the cost is also reduced. The performance of the traditional light source can reach 10 - 100 lm/W, while LED can only reach up to 25 lm/W - manufacturers hope that by the end of 2007, up to 75 lm/W.

High power LED is currently under development, but they are also facing other production problems, such as heat dissipation is poor (which will reduce the life of the LED), etc..

So when you want to buy LED lamps to illuminate, please think twice. LED has not yet reached (at least for now) the level of replacing traditional lamps in a variety of applications. With the continuous development of science and technology, continuous improvement of new products have been available, perhaps a few years later, LED can achieve the desired level. But in the current output, LED can not compete with traditional lamps. Naturally, the question is: why would LED be regarded as an economic product? Well, as a matter of fact, if you choose wisely, they do have the same effect.

LED production

In the field of solid state lighting, organic and inorganic semiconductors are used to produce light-emitting diodes. Therefore, from this perspective, we can also be divided into two categories of light sources: inorganic semiconductors - LED, and organic semiconductors - OLED.

In 1907, scientists Henry Joseph Round observed in the observation of corundum (SiC) called electroluminescence phenomenon, the first observation of the luminescence of inorganic semiconductors. But because of the faint glow of an inorganic semiconductor, he soon gave up the study. In 1962, General Company Nick Holonyak led a team to successfully demonstrate the first light emitting diode, after only 6 years, the research and development of Monsanto indicator and Hewlett-Packard development of electronic display will be the commercial LED market.

By 1980s, the first generation of ultra bright LED (GaAlAsP) was born. The product is red, yellow, and green. Subsequently, by 1990s, InGaAlP (indium gallium aluminum phosphorus) combination was used