Outdoor LED screens are more and more widely used, but the quality is uneven and the accidents are frequent, so how can we judge the quality of outdoor LED?
Nowadays, with the rapid development, outdoor LED screens are more and more widely used, but the quality is uneven and the accidents are frequent, so how can we judge the quality of outdoor LED?
In the LED display disk, the most important is the LED lamp bead, the quality of the lamp bead is affected LED screen quality. LED lamp bead is spoken by the largest number of the key device in the full color machine, every square metre can use only a few thousand to tens of thousands of lights, lamp bead is to determine the main body of the whole screen optical display performance, a direct impact on the audience evaluation for display, light bead on the screen as a proportion of the overall cost is also the biggest, ranging from 30% to 70%. The importance was immediately apparent.
In the field of LED display, one of the most important index is brightness, under the high requirements for brightness, heat will become a big problem, heat dissipation is field both lighting and LED display is a relatively old problem. Manufacturers have launched their own cooling solutions, and the declaration of their product's cooling effect has become a hard target. The other reason is that with the development of small spacing leds, the problem of the knot temperature is always difficult to solve.
So how do you distinguish the light from the LED?
The first: to see brightness, is to say how many LM (lumen) is your lamp bead, LM (lumming) is the unit that measures the luminosity of the lamp.
Second: whether the light is uniform or not, the good light of quality is uniform and the color is consistent. The quality of the lamp bead can appear a lamp bead brightness is bright, the phenomenon of a lamp bead is dark, the color of luminous color is not unified, can have obvious dark area.
Third: the chip and chip size, the chip is the decision factor of the quality of the bead quality, generally the bigger the chip, the stronger the stability, the higher the brightness, the better the heat dissipation.
Fourth: see glue and phosphor, generally good product will use imported glue, sealed the lamp bead hand press deformation, low quality of the glue one click will appear the phenomenon such as deformation and cracking.
Fifth: look at the stent, the general condition is silver-plated red copper stents, the advantage of silver-plated red copper stents is that the heat dissipation is faster, which can better heat the bulb and lower the resistance. Some merchants in the market will replace the silver-plated copper stents with ceramic brackets. The thermal conductivity of ceramic supports is excellent
Sixth: look at the packaging process, the quality of the LED lamp bead color uniform, the colloidal consistency is good. It is inseparable from good machinery and equipment, the production of machinery and equipment is a key factor, good equipment can guarantee the stability of the product on each program and consistency, the yield of security products.
In fact, the most important thing is the chip, which directly determines the degree of color index, brightness and anti-attenuation.
In the case of high junction temperature, the light failure can be very serious,
The first contact body of heat is the base plate, and the heat conduction of the base plate will determine the temperature directly. Now, some of the well-known manufacturers are already using new ceramics as substrate materials.
Ceramic substrate as the best heat dissipation effect on the market, it is better than aluminum substrate, silicon substrate and sapphire substrate. The ceramic substrate currently has two main types of aluminum nitride and alumina, and the thermal conductivity of aluminum nitride can reach 170 (W/m • K) ~ 230 (W/(m • K). It's more than twice the size of alumina. This kind of thermal conductivity, LED lamp bead basically does not have knot temperature generation, also do not have heat dissipation problem.