How to use LED display
Author:Li Qiuyu Time:2021-06-09 13:32 Browse(998)
Need software, rely on software to edit the above words, the operation is very simple, just like with QQ, the role of the cable is to edit the file through the cable sent to the screen.
If you need software, you can edit the above words by software. The operation is very simple, just like using QQ. The function of the network cable is to send the edited files to the display screen through the network cable.

How to use LED display

when you use the network cable to edit the above words, you can use the software to edit them
LED screen is a new type of imaging electronic equipment made of light-emitting diodes arranged in order The structure and light-emitting principle of LED 50 years ago, people had already known the basic knowledge that semiconductor materials can produce light.
the first commercial diode was produced in 1960.
LED is the abbreviation of light emitting diode in English.
its basic structure is an electroluminescent semiconductor material, which is placed on a shelf with leads, and then sealed with epoxy resin, The core part of LED is a wafer composed of p-type semiconductor and n-type semiconductor.
there is a transition layer between p-type semiconductor and n-type semiconductor, It is called p-n junction.
in some PN junctions of semiconductor materials,
when the injected minority carriers are combined with the majority carriers, the excess energy will be released in the form of light, so that the electric energy can be directly converted into light energy.
it is difficult to inject the minority carriers in the PN junction with reverse voltage, So it doesn't emit light.
this kind of diode based on the principle of injection electroluminescence is called light-emitting diode.
it is generally called led.
when it is in the positive working state (that is, the positive voltage is applied at both ends).
when the current flows from the anode to the cathode of the LED, the semiconductor crystal emits light of different colors from ultraviolet to infrared, and the intensity of light is related to the current.
this kind of diode is called led2、 Characteristics of LED light source 1. Voltage: LED uses low-voltage power supply.
the power supply voltage is between 6-24 V, which varies according to different products, so it is a safer power supply than using high-voltage power supply, It is especially suitable for public places.
2. Efficiency: energy consumption is 80% less than that of incandescent lamps with the same luminous efficiency.
3. Applicability: very small.
each unit led chip is 3-5mm square, so it can be fabricated into various shapes of devices, Stability: 100000 hours.
light decay is 50% of the initial.
5. Response time: the response time of incandescent lamp is millisecond level.
the response time of LED lamp is nanosecond level.
6. Environmental pollution: no harmful metal mercury.
7. Color: changing current can change color.
LED can be easily chemically modified Methods: adjust the energy band structure and band gap of the material to achieve red, yellow, green, blue and orange multi-color luminescence.
for example, the LED is red when the current is small.
with the increase of current, it can turn into orange, yellow, and finally green.
8. Price: the price of LED is more expensive.
compared with white incandescent lamp, the price of several LEDs can be equivalent to that of an incandescent lamp, In general, each group of signal lamps should be composed of 300-500 diodes.
3. The types and development history of monochromatic LED. The first LED light source based on semiconductor p-n junction light-emitting principle came out in the early 1960s.
the material used at that time was GaAsP.
emitting red light( λ When the driving current is 20 mA, the luminous flux is only a few thousandths of lumen,The corresponding luminous efficiency is about 0.1 lumen / W.
in the mid-1970s.
the introduction of elements in and n makes the LED produce green light( λ P=555nm), yellow light( λ P=590 nm) and orange light( λ In the early 1980s, GaAlAs LED light source appeared, making the light efficiency of red LED reach 10 lumen / W.
in the early 1990s, the successful development of GaAlInP with red and yellow light and GaInN with green and blue light has greatly improved the light efficiency of LED.
in 2000, the LED made of GaAlInP with red and yellow light and GaInN with green and blue light has been widely used in the fields of red and blue light Orange District( λ The light efficiency of the LED is 100 lumen / w (P=615nm)( λ (P=530nm) can achieve 50 lumen / W.
4. The application of monochromatic LED was initially used as the indicator light source of instruments and meters.
later, various light colors of LED were widely used in traffic lights and large area displays, resulting in good economic and social benefits.
take the 12 inch red traffic lights as an example.
in the United States, long life was originally used, The 140 watt incandescent lamp with low luminous efficiency is used as the light source, which produces 2000 lumens of white light.
after passing through the red filter.
the light loss is 90%, leaving only 200 lumens of red light.
in the newly designed lamp.
Lumileds uses 18 red LED light sources, including the circuit loss, which consumes 14 watts, The same light efficiency can be produced.
the automobile signal lamp is also an important field of LED light source application.
the automobile signal lamp is an important field of LED light source applicationIn China, high mounted stop lights have been installed on cars. Due to the fast response speed of LED (nanosecond), it can let the driver of the following vehicle know the driving condition as soon as possible and reduce the occurrence of rear end collision accidents.
in addition,
LED lights have been applied in outdoor red, green and blue full-color displays, keychain mini torches and other fields.
v The development of white LED is more important for general lighting.
people need white light source.
the white LED was successfully developed in 1998.
this kind of LED is made of Gan chip and yttrium aluminum garnet (YAG) packaged together.
Gan chip emits blue light( λ The blue LED substrate is mounted in a bowl shaped reflecting cavity.
it is covered with a thin layer of resin mixed with YAG, about 200-500nm.
part of the blue light emitted by the LED substrate is absorbed by the phosphor.
another part of the blue light is mixed with the yellow light emitted by the phosphor, White light can be obtained.
for InGaN / YAG white LEDs, by changing the chemical composition of YAG phosphor and adjusting the thickness of phosphor layer, All kinds of white light with a color temperature of 3500-10000k can be obtained.
Table 1 lists the types of white LEDs and their luminescent principles.
the first product that has been commercialized is blue light single crystal chip with YAG yellow phosphor.
its best luminous efficiency is about 25 lumen / W, and most of YAG is.
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