Do you know how LED displays work
Time:2018-10-24
Views:221
An LED, a light-emitting diode, is a solid-state semiconductor device that converts electrical energy directly into light energy.The heart of the LED is a semiconductor wafer, which is encapsulated in an epoxy resin.A semiconductor wafer is made up of two parts, one of which is a p-type semiconductor, in which holes dominate, and the other is an n-type semiconductor, in which electrons dominate.But when the two semiconductors are connected, they form a "p-n junction", which is the equivalent of an electric field.And when the electrons come in, they‘re rejected by the negative pole, which is the N pole, and they‘re pushed to the positive, which is the P region, where the electrons and the holes come together, and they give off energy in the form of photons, and that‘s how leds work.The color of light (the wavelength of light) is determined by the formation of p-n junction material.
The luminous color and luminous efficiency of LED are related to the materials and process of making LED. Currently, three kinds of LED are widely used: red, green and blue.As the working voltage of LED is low (only 1.5-3v), it can emit light actively and has a certain brightness. The brightness can be adjusted by voltage (or current), and it is resistant to impact, vibration and long life (100,000 hours, that is, 11.4 years).The materials used to make leds differ, producing photons of different energy that control the wavelength, or spectrum, of the light they emit.
The brightness attenuation cycle is closely related to the material manufacturing process of LED production. Generally, four elements LED with slow attenuation should be selected when economic conditions permit.Match color, white balance: white is red, green and blue tricolor is mixed by brightness scale and become, when the brightness of green in the light is 69%, the brightness of red is 21%, the brightness of blue is 10%, what mixed color posterity eye feels is pure white.Early CRT TV sets to present the LCD is composed like this.
The red, green and blue lines emitted by the LED can be roughly divided into purple red, pure red, orange red, orange, orange yellow, yellow, yellow green, pure green, emerald green, blue green, blue and purple according to the characteristics of different wavelengths and can be roughly divided into red, yellow, green, blue and purple. The price of orange red, yellow green and blue purple is much cheaper than that of pure red and green.Green is the most important of the three primary colors, because green occupies 69% of the brightness in white and is at the center of the color list.Therefore, the three-base color composition between the purity of color and the price is balanced. In the application of three-base color design, the white balance and the maximum expected brightness can be achieved by adjusting the set LED current.
An LED can emit light of three colors in two cases: an LED of three colors can be used in this lamp, for example, red, yellow, green and blue light beads can be emitted respectively. In this way, when different light beads are energized, a variety of colors can be emitted.In another case, a "two-color light-emitting diode" is used. When the corresponding electrodes are loaded separately, they emit two colors of light, while when they are loaded simultaneously, they emit a mixture of the two colors of light.
The reason why LED lamp has a large pearl fading: there are four reasons for the attenuation of low-power LED:
1. Poor thermal conductivity of iron bracket;
Two, epoxy resin xanthation;
Third, chip and bracket are not close enough in contact;
Four, chip attenuation is big.If it‘s white light, there‘s also the problem of phosphor attenuation.
LED display, using IC control and other color display.The main performance is modular IC control, an IC control multiple lights, the advantages are dense, high brightness, strong.The disadvantages are high cost, high power consumption, high heat, easy leakage and difficult maintenance.
Now we have a new product, which is a large display screen with multiple light strips.One lamp is equipped with a simple IC. The advantages are light weight, low cost, good waterproof (lamp bar one by one sealing glue), easy to move, maintenance and installation.The disadvantage is not bright enough, wide spacing, also not suitable for outdoor!
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