1879, the United States Edison invented a practical value of carbon filament incandescent lamp, human from the long fire lighting era into the era of electric lighting.The first tungsten filament incandescent lamp appeared in 1907.In 1912, the gas-filled incandescent lamp appeared, and its luminous efficiency and life are higher than the non-gas-filled incandescent lamp.
In 1932, philips introduced the low - pressure sodium lamp.In 1938, phillips produced the first fluorescent lamp, which was more than three times the luminous efficiency and life of incandescent lamp, which was a big breakthrough in the technology of electric light source.In the 1940s, high-pressure mercury lamps came into use.In the 1950s, the halogen tungsten lamp with small volume and light decay came out, which changed the state of slow progress of thermal radiation light source technology. This is another big breakthrough of electric light source technology.In the 1960s, neon, metal halide and high pressure sodium lamps came into being.
In 1972, philips introduced the second generation of thin tube (T8) energy-saving fluorescent lamps and fluorescent high frequency electronic ballasts.Compact energy-saving fluorescent lamp, thin tube diameter, ultra low mercury energy-saving fluorescent lamps, small power high-pressure sodium lamp, low power metal halide lamp, neon light, high brightness leds, ultrafine diameter cold cathode tube and multi-functional electronic ballast appeared, and poured into the market, make the electric light source into the miniaturization, efficient., energy saving, environmental protection, a new era of standardized and electronic.
In the past two years, with the emergence of ultra-bright white LED, the application of LED in the lighting field has become possible.The future of leds in the lighting market is under global scrutiny amid renewed concerns about global energy shortages.According to the prediction of international authority, in the next 10 years, LED will become the most potential new light source to replace incandescent lamp, halogen tungsten lamp and energy-saving fluorescent lamp.
The 21st century will enter the era of new lighting source represented by LED (known as the era of the fourth generation of new light source).It has also been pointed out that the high brightness LED will be one of the greatest inventions since Edison invented the incandescent light bulb.
