Editor's note: Since the introduction of Light-Emitting Diode (LED) in 1962 (using GaAsP materials, red LEDs), after one or two decades of development, there are generally several types of applications as follows: 1. Visible LEDs, Status light indication, toy, Christmas tree lighting 2. Infrared LED, home appliance remote control, anti-theft sensor, fire smoke detection 3. Optical fiber transmission, digital logic 0/1 state representation, change the voltage level to the LED clear signal Replacing 4. Various laser applications, such as CD laser discs, laser pointers for presentations, laser printer indicator and infrared sensing, control, make people feel quite pediatric technology, but fiber and laser are still in the bulk Progressive technology, in addition to these LEDs have a more amazing development, that is to move toward the field of electronic lighting, and this must be attributed to the efforts and breakthroughs of the LED industry in the past decade, the practical use of blue LEDs in 1993 After the successful development, it can start to produce white LEDs through the flexible synthesis technology, such as blue LED + yellow phosphor, or blue LED + red and green phosphor, or ultraviolet LED + red, green and blue.
Note: In fact, as long as the LED transparent plastic is used in different colors, it can naturally produce different illuminating colors, but the focus is on luminous efficiency, which is why the blue LED cannot be created for a long time in the past (low efficiency), more specifically Under the same power consumption, the brightness equivalent to the mature red LED and yellow LED cannot be obtained.
Ten advantages of W-LED With the efficient white LED (White LED or WLED, W-LED), LED officially enters the application of electronic lighting. What are the advantages of LED and electronic lighting? What? For the author, one by one:
1. The cold light source is a cold light source with less waste heat than the white light lamp (the incandescent light bulb of the tungsten filament electrothermal light), and is the same as the fluorescent lamp (the gas discharge light-emitting fluorescent tube).
2. High energy saving Compared with white light, W-LED has better luminous efficiency, but it is still lower than fluorescent light, and it is actively working hard to improve.
3. Solid-state light is not like fluorescent lamps, neon lamps, high-pressure gas discharge lamps (HID), cold cathode fluorescent lamps (CCFL), etc., which emit light by means of gas discharge. Such luminescence methods are mostly used to discharge mercury vapor in a sealed tube. Mercury is harmful to the environment and can overflow if the lamp is broken.
4. High seismic resistance is not like gas light pipe technology such as fluorescent lamps. Once the external force is applied, the light pipe will be broken, which will not only cause environmental hazard, but also cannot continuously emit light after damage. Therefore, W-LED is very suitable for use in automobiles and mines. Taste the harsh environment such as industrial control.
5. High environmental protection W-LED does not have the aforementioned mercury components, and does not require light pipe recovery, and the damage will not affect the ecological environment.
6. Long life The life of W-LED can reach tens of thousands of hours, the same level as fluorescent tubes, even beyond, and far better than thousands of hours of white light.
7. After the reaction is fast, it can be completely lit in only a few microseconds. The opposite fluorescent tube will flash for a few seconds to fully illuminate, or even longer.
8. Easy to drive W-LED only needs 3.0V ~ 3.6V DC drive voltage to light up, so as long as the simple one or two AA dry batteries can be used, and the light pipe type lighting mostly needs periodic positive and negative AC power, the power supply design is more complicated.
9. High-health light tube lighting will have the flickering of the AC frequency. The long-sighted eye is easy to use, fatigue and even hurt. Therefore, many PL lamps for reading will increase the frequency, thereby reducing the burden on the eyes, while W-LED belongs to Continuously lit, no flickering problems.
10. High safety As mentioned above, the W-LED can be driven only by a weak voltage. However, the HID lamp for the vehicle needs high voltage (up to 23,000 volts) to be driven. Therefore, professional maintenance personnel are required to change the package. There is a significant risk of electric shock.
In addition to the above 10 advantages, the other includes lighter and thinner temperature stability than general electronic lighting components, but in addition to the advantages of incentives, there are also pressures of non-traffic W-LED as electronic lighting, this pressure is mainly There are two:
1. The Kyoto Protocol limits the emission of greenhouse gases, making energy-saving electricity an increasingly urgent problem, especially the need to eliminate too much heat-consuming and inefficient white light.
2. Restriction of Hazardous Substances Directive (RoHS), the EU stipulates that no hazardous substances should be used in imported goods in July 2006, including lead, mercury, hexavalent chromium, PBB (polybrominated biphenyl), and PBDE (polybrominated diphenyl). Ether), etc., also includes the requirements of Waste Electrical and Electronic Equipment (WEEE), so that the light pipe type illumination using mercury gas discharge can not be reused, even if its luminous efficiency is better, and not only Europe The common market has such a requirement, and other advanced countries such as Japan have begun to propose similar controls, which will gradually become a global environmental consensus. Allegro Introduces 3-Channel Constant Current LED Driver
Zhen Mingli will increase its monthly output of LED lights to 400 million next year
Hong Kong develops the latest LED LED lighting technology
Toshiba launches high-gloss flux surface mount white LED
LED backlight output value of 1 billion US dollars in 4 years
Comparison of LED light source and neon light
Semiconductor LED lighting fixtures enter the mainland market
LED lighting and backlighting are used in the color screen market
1 