Five leds technology development problem to be solved
LED lighting, LED display screen are energy saving, environmental protection products. LED lights than incandescent lamp has obvious advantages, but suffer from domestic development later, had mastered the core technology, the high price is difficult to popularize. In view of this, experts put forward the future of LED lamps and lanterns around to solve the following five technical difficulties in direction.
Improve the efficiency of the LED power supply
Whether do current limiting the power of the constant current control, and operational control constant current power supply, to solve the problem of power supply. That is, switching power supply chip work is need a relatively steady dc voltage for power supply of the chip, chip the working current of ranging from a MA to several MA. Like FSD200 NCP1012, and HV9910, this kind of chips are the high voltage from the feed, is convenient to use, but high pressure feed, cause IC heat rise, because the IC to about 300 v direct current, as long as a little bit current, even if a MA, also have the damage loss of zero point three watts. General led power supply 10 watts around, however, it is ok to loss of a tile of the efficiency of power supply is down a few points. The typical like QX9910. With pull electrical resistance, in this way, the loss on the resistance, also get lost nearly zero a few watts. And the magnetic coupling, it is a transformer, the main power upon a coil winding, like the auxiliary winding of the flyback power supply, so that you can avoid damage of the tenths of watts of power. This is one reason why not isolation power supply and transformer, in order to avoid losses that tenths of watts of power, to raise efficiency of several points.
Improve reliability of LED lighting system
The overall efficiency, service life and reliability of the leds must be through the system optimization to ascend.
Light source: compact, efficient, choose the right color and power output.
Control and drive: use electronic circuit realization LED constant current drive and control.
Thermal management: if you want to achieve a longer service life must control LED node temperature, heat dissipation model calculation and application of new materials, new technology is a hot spot in the LED technology.
Optical element: lens, reflector, or guide plate material is to focus light on the target area or scattered around, depending on the design requirements.
Improve the leds luminous efficacy
Improve the light efficiency can also be from raising the proportion of light effectively. Thin film chip technology can reduce the loss of the light output of each side with the help of a reflecting surface at the bottom of the to make more than 97% of the light output from the front, makes electricity into light, for the most part, are effective light, not only significantly improve the LED lights, also created a favorable conveniences for lens design. Thin film chip technology is the core technology of ultra bright LED chip production.
Improve the LED color rendering
A small part in high brightness white LED, blue light occurs after the stokes shift has a longer wavelength. This is a good thing, because it makes the LED lamp manufacturers can use many different colors of phosphor layer, so as to extend the emission spectrum, effectively improve the LED color rendering index (CRI). Adopt the phosphor white LED to obtain high CRI comes at a price, because the stokes shift will cause the efficiency is lower than the monochrome leds efficiency of white LED. But for most of the lighting applications, would rather choose high CRI and slightly lower efficiency of leds.
Reduce the cost of LED lights
Led chip occupies the main part of the cost of led lights, and the main way to reduce the cost of the led is to reduce the cost of the led chip. The key to the development of the LED chip technology is the base material and epitaxial growth technology. Basal materials from the traditional material, silicon and silicon carbide, sapphire to zinc oxide, new materials such as gallium nitride. In just a few years, with the aid of including chip structure, surface roughening treatment and multiple quantum well structure design of a series of technical improvement, achieved great breakthrough in the field of photosynthetic efficiency of LED.
Silicon substrate cost is low, technology in progress, but still not satisfied, luminous efficiency if keep the development speed, once reached a higher level, then silicon substrate will be the main technology solutions become inevitable choice, companies will gain great economic returns.