In recent years, this new type of lighting is increasingly appearing in our lives, from liquid crystal displays backlit by light-emitting diodes to desk lamps illuminated by them. So, what are the advantages of light-emitting diodes compared with traditional lighting methods, and how do they provide lighting for us?

Incandescent: Before we understand how light-emitting diodes work and why they are more energy efficient, let's take a look at how traditional incandescent lamps, commonly known as light bulbs, emit light.

You might be surprised if I told you that everything around us glows. Yes, common sense tells us that only stars in the sky can emit light, and even the moon reflects light. In our life, apart from electric lights, candles, etc., have we not seen other objects glowing?

Scientists tell us that as long as its temperature is higher than absolute zero, any object will emit energy to the outside world in the form of electromagnetic waves all the time, which is called thermal radiation. The wavelength of electromagnetic waves ranges from thousands of kilometers to less than 1 nanometer, spanning a huge range, but only a narrow segment of 400-800 nanometers can be perceived by our eyes, which is commonly referred to as visible light. So we can say that all objects, including ourselves, emit light.

However, the electromagnetic waves emitted by an object do not cover all wavelengths uniformly, but are mainly concentrated near a certain wavelength, and the length of this wavelength is inversely proportional to the temperature of the object. For objects with a temperature around room temperature, the electromagnetic waves emitted by them are mainly concentrated in infrared rays with longer wavelengths than visible light, so the proportion of visible light is very small. That's why we can't see these objects glowing.

As the temperature of an object increases step by step, its thermal radiation will not only become more intense, but also the electromagnetic waves emitted will gradually become dominated by visible light, so these objects that were originally invisible will become brighter. For example, when the electric furnace wire is heated to several hundred degrees Celsius, it will turn red, because the increase in temperature makes red light replace infrared light and occupy a dominant position in thermal radiation. If the temperature continues to rise to several thousand degrees Celsius, the shorter wavelengths of yellow, green, blue and other colors of visible light are also released in large quantities. When visible light of different wavelengths is mixed together, we see white light similar to sunlight, which is incandescence.

Before the advent of incandescent lamps, people burned firewood, lamp oil or candles for lighting. In fact, they were using incandescent phenomena, but at this time, they used the high temperature generated by chemical reactions; while incandescent lamps used electric current to heat tungsten filaments to Above 2000 degrees Celsius, resulting in a large amount of visible light.

From the perspective of energy conversion, when the incandescent lamp emits light, a large amount of electrical energy will be converted into heat energy, and only a very small part can be converted into useful light energy. LED lights directly convert electrical energy into light energy. The energy conversion of incandescent lamps is mainly to generate heat, and then to emit light. LED lamps mainly emit light, and then only to generate heat. It is precisely because of the small size, low current, low power consumption, long life, environmental protection and energy saving of LED lights that they are currently used more.