As early as 1962, people developed visible light-emitting diodes. In the early days, LEDs were used as indicator lights on instrumentation. Later, they were gradually commercialized and used. In the past decade, LEDs have been widely used in lighting and display fields. The following is the development history of LED:
In 1962, a red-emitting light-emitting semiconductor was developed by a joint laboratory of GE, Monsanto, and IBM.
In 1965, the world's first light-emitting diode was successfully developed. It can emit infrared light-emitting diodes. At that time, the LED was very expensive, about RMB 300/W, and only 0.1 lm per watt. The traditional incandescent lamp ratio At that time, the luminous flux was more than 100 times higher.
In 1968, with the unremitting efforts of researchers, LEDs have developed greatly. By 1968, LEDs had 1 lm/W, and they could emit red, orange, and yellow light.
In 1971, there was a green chip.
By the 1970s, the price of LEDs had dropped dramatically.
In 1994, Japanese scientists developed the first blue LED light-emitting diode.
In 1996, the Japanese company developed the first white LED light-emitting diode.
In the late 1990s, light-emitting diodes that produced blue light by YAG phosphors were developed, but the effect was not good, the life was short, and the price was high.
With the continuous advancement of technology, the development of LED is very fast. At present, LED light efficiency can reach 200lm/W. It has been praised as the fourth revolution in the field of human lighting. In the past ten years, LED has been widely used in lighting, After display and other fields, the largest market for LEDs will be in the field of lighting, especially in mainland China.
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