Discussion: LED represents the pinnacle of LED lighting technology

Compared with those who are often a year or even six months to update the generation of consumer electronics products, the bulb is too lonely. Edison invented the first tungsten filament bulb has been in the past 132 years, but the revolutionary changes in lighting technology are few, let alone a disruptive breakthrough.

Now, the dawn.

Before the end of 2012, if all goes well, you may see a peculiar shape of the bulb in the market: a total of 4 light emitting cavity between the cavity and the cavity and four cracks for cooling, the central radiator, the tail of the installation of electronic control system of the complex, used to adjust the intensity of light. The name L Prize bulb from PHILPS, it is likely to represent the future of a new generation of lighting technology.

The technology used in L Prize is LED (light-emitting diode), but this is by no means the reason for it to become a new generation of lighting spokesmen. The semiconductor wafer + Phosphor "as the core of the LED lighting first appeared in 1962, the GE company, it was first used in radio, small computer and electronic watches, was moved to the lighting field only in recent years.

The reason why L Prize is mentioned in particular is that it has reached the peak of LED home lighting technology: it can not only achieve the incandescent lighting effect, but also greatly improve the efficiency of energy use. Its energy efficiency (power conversion efficiency) is 10 times the incandescent lamp, fluorescent lamp is 1.6 times, while the same as the perfect incandescent lamp. If these mouthful term together into a picture, then it should be such a scene: you stand in a very pleasant warm white light, but this time for each color every photo you take on can accurately restore.

It's not an easy thing to do. In an interview, Liu Ye, director of project management at PHILPS lighting, LED lighting, which was part of the research and development company, said that at first they thought the technical standards were "abnormal"".

PHILPS as early as June 2008, the world began to call LED chip and electronic control experts, European experts, Shanghai phosphor production experts, more than and 100 people in the United States team, divided into pre concept, product design and business plan in three phases, into research and development of L Prize. The move is a response to the U.S. Department of energy bill. The latter decided this year, for the first to develop LED bulb can replace 60 watt incandescent light bulb with a $10 million reward, and writes it to the United States "2007 energy independence and Security Act", the premise is the product to meet those harsh index.

Relative to the LED lighting needs R & D investment, $10 million is simply a drop in the ocean. But PHILPS is also aware that if the product can be successfully developed, it will bring considerable government procurement contracts and market leading ability.

This is not the first attempt to find alternatives to incandescent lamps. Although the incandescent light source is perfect, but its energy conversion rate is too low, only 10lm/W, incandescent 90% of the energy is wasted on the heat.

Before LED, the fluorescent lamp (i.e. energy-saving lamps) had been high hopes, the average energy conversion efficiency can reach 5060lm/W. But one of the main characteristics of fluorescent lamp is that the higher the conversion efficiency of light energy, the better the appearance of straight tube. These features in many European and American families seem unacceptable, not many people are willing to in their own home lamp on the ceiling of a straight hair, a cold white light; in Chinese, is roughly the same, many families in order to avoid the color too cold, will be installed in the incandescent lamp fluorescent lamp light belt.

Color temperature is a big problem to be solved in the development of L Prize. Prior to the LED lighting technology and the existence of a fluorescent lamp with the same problem, that is, the more warm the lighting, the more red phosphor used in LED lamps, the efficiency will be greatly reduced. In addition, the U. S. Department of energy's standard lamp life must be greater than 25 thousand hours, almost times the average life of existing LED bulbs.

In order to solve the problem of color temperature, L Prize R & D team in the usual blue chip LED beside the red chip LED, the use of red phosphors to achieve greater efficiency than the warm color. In addition, the traditional fluorescent powder directly affixed to the wafer, as time passes, easy to heat, the loss of light is also very large. In order to meet the stringent standards of more than 90lm/W, PHILPS developed a technique called "phosphor Remote Phosphor" mixing cavity, fluorescent powder is no longer directly attached to the wafer surface, but have a certain distance, let all kinds of light can be fully mixed in the internal cavity, greatly improving the efficiency.

Let them feel that the most difficult thing is that the U.S. Department of energy's standard LED lamp must be like a tungsten lamp, the light can be scattered around, to achieve a full range of around (light all). "This is the inherent advantage of tungsten lamp, it was born so. But LED can't do it. He said.

Tungsten lamp bulb structure is very simple, in addition to the luminous outside of the tungsten wire, surrounded by almost all transparent glass, only the bottom of the interface will block the scattering of light. And most of the traditional LED lamp is designed into a hemisphere, placed at the bottom of the LED chip and heat sink, only 180 degree light scattering.

Another problem is the radiator, the team wanted to use liquids and even fans, and ultimately decided to use the most traditional mechanical devices, because the most