Common sense of led screen

What are the precautions for 1.LED display?

Note: 1. Switch sequence: when the screen is turned on, turn it on first and then turn it on.

When turning off the screen: turn off the screen first, then turn off (turning off the computer without turning off the display screen first will cause the screen to be highlighted, and the led will burn out the lamp tube, with serious consequences. ) 2. The interval between switching screens should be more than 5 minutes.

3. Before the computer enters the engineering control software and turns on the screen power. 4. Avoid opening the screen in the state of full white screen, because the impact current of the system is the largest at this time.

5. Avoid opening the screen when it is out of control, because the impact current of the system is the largest at this time. The computer has no input control software and other programs; B. the computer is not turned on; C the power supply of the control part is not turned on.

6. When the ambient temperature is too high or the heat dissipation condition is not good, LED lighting should be careful not to turn on the screen for a long time. 7. When the lines on a certain part of the electronic display screen are very bright, attention should be paid to closing the screen in time, and it is not advisable to open the screen for a long time in this state.

8. The power switch of the display screen often trips. Check the screen or replace the power switch in time. 9. Regularly check the firmness of the hook.

If there is looseness, pay attention to timely adjustment, re-reinforce or update the hanger.

2. Who can tell me the basic knowledge of LED display?

LED (Light Emitting Diode) is a solid-state semiconductor device, which can directly convert electricity into light.

The heart of LED is a semiconductor chip, one end of which is attached to the bracket, one end is the negative electrode, and the other end is connected to the positive electrode of power supply, so that the whole chip is encapsulated by epoxy resin. The semiconductor wafer consists of two parts, one is a P-type semiconductor, in which holes are dominant, and the other is an N-type semiconductor, mainly electrons.

But when these two semiconductors are connected together, a "pn junction" is formed between them. When the current acts on the chip through the wire, the electrons will be pushed to the P region, where they will recombine with holes and then release energy in the form of photons, which is the principle of LED light emission.

The wavelength of light determines the color of light, and the color of light is determined by the material that constitutes the pn junction. LED is a semiconductor that can convert electric energy into light energy. It changes the principle of incandescent tungsten filament luminescence and energy-saving lamp tricolor powder luminescence, and adopts electric field luminescence.

According to the analysis, the characteristics of LED are very obvious, such as long life, high light efficiency, no radiation and low power consumption. The spectrum of LED is almost completely concentrated in the visible light band, and the luminous efficiency can exceed 150lm/W(20 10 years).

Comparing LED with ordinary incandescent lamp, spiral energy-saving lamp and T5 tricolor fluorescent lamp, the results show that the light efficiency of ordinary incandescent lamp is 1.2 lm/w, and its service life is less than 2000 hours. The power of spiral energy-saving lamp is 60lm/W, and its service life is less than 8000 hours. The power of T5 fluorescent lamp is 96lm/W, its life is about 1000 hours, and its diameter is 5 mm. It is also predicted that the upper limit of LED life will be infinite in the future.

However, the working principle of LED lamps makes the heat dissipation problem very prominent in the high-power LED lighting industry. Many LED lighting schemes do not pay enough attention to heat dissipation, or their technical level is limited. Therefore, the actual service life of high-power LED lamps in mass production is far less than the theoretical value, and the cost performance is higher than that of traditional lamps. In order to prolong the service life of LED lamps and truly make them suitable for commercial mass production, the LED lighting industry is stepping up its efforts to develop new heat-conducting materials such as heat-conducting plastics independently or in cooperation with professional heat-conducting material suppliers.

High power, generally refers to greater than 0. 65W, which will have different standards in different companies, because there is no recognized industry standard in the field of high-power LED.

The ratio of light intensity to lumen is small, but the heat dissipation is also large. At present, high power is mostly used in a single application, and the effective heat dissipation area is large, so the integrated LED lamp matrix appears, but the heat dissipation effect is not very good. Low power is generally 0.

06W or so. At present, LED flashlights generally use low power, and the light does not diverge, depending on the light emitting angle of LED, which can be divided into large angle and small angle. Small angles don't spread, big angles only spread.

Flashlights on the market are generally made of straw hats. The effect is very good.

Now I'm worried that some manufacturers don't pay attention to quality and use inferior LEDs as flashlights. It won't be long before there are dead lights. The brightness of LED must be related to the light emitting angle of LED. The smaller the LED angle, the higher the brightness. Nothing is super bright, it's a lie to children. If it is a good quality LED, no matter which LED manufacturer produces it, everyone's brightness is similar, but the production process is different and the service life is slightly different, because everyone uses those foreign LED chips.

If it is a 5MM LED with an angle of 180 degrees, the brightness of white light is only a few hundred MCD. If it is an angle of 15 degrees, it will reach the brightness of 1 10,000 to 20,000 MCD, and the brightness difference is dozens of times. If it is used for lighting, it is best to use high-power LED outdoors for higher brightness. Single power 1W, 3W, 5W, and so on. Color temperature has nothing to do with brightness, but brightness is related to lumen value. Let's look at several related concepts: luminous flux (lm) Because human eyes have different sensitivities to electromagnetic waves of different wavelengths, we can't directly measure light energy by the radiation power or radiation flux of a light source, but must use the unit based on human eyes' perception of light-luminous flux.

The luminous flux is indicated by the symbol φ, and the unit is lumen (lm). Luminous intensity (cd) luminous flux is the total light energy emitted by a light source to the surrounding space.

The spatial distribution of luminous flux emitted by different light sources is different. The unit of luminous intensity is Candeira, and the symbol is cd, which indicates the luminous flux emitted by the light source within the unit spherical solid angle (the angle formed by the surface of the object and the point light source).

1CD =1lm/1Sr (Sr: spherical unit of solid angle). Brightness (cd/m2) Brightness is the intensity of light emitted by an object seen by the eyes from a certain direction.

The unit is Candeira /m2 [cd/m2], and the symbol is L, which indicates the luminous flux of the luminous body in the unit area of the solid angle in a specific direction, which is equal to the luminous intensity emitted by 1 Candeira from the surface of 1 m2. Color temperature When the color of light emitted by a light source is the same as that radiated by a blackbody at a certain temperature, the temperature of the blackbody is called the color temperature of the light source, and the absolute temperature k (Kelvin = 273 degrees Celsius) is used.

15). color rendering in principle, artificial light should be the same as natural light, so that people can correctly distinguish the color of things with the naked eye. Of course, it depends on the location and purpose of lighting.

The degree to which a light source presents the color of an object is called color rendering. Commonly referred to as "color rendering index" (Ra).

Color rendering refers to the relationship between the true color of things (their own color) and the color displayed under a standard light source. The determination of Ra value is to compare eight test colors defined in DIN6 169 standard with the measured light source. The smaller the color difference, the better the color rendering of the test light source color.

A light source with Ra value of 100 indicates that the color displayed by things under its light is the same as that under the standard light source. Edit the basic information of this paragraph.

What are the classifications of 3.3? LED electronic display?

Compared with other LED structures and incandescent light sources, the luminous efficiency of transparent substrate A 1GaInP LED is higher than that of GaASP-GaP LED in the wavelength range of 590-626nm, and the absorption substrate (As) is 10 1m/w and the transparent substrate (TS) is 201m. In the wavelength range of 560-570, it is 2-4 times higher than GaAsP-GaP LED.

Ultra-high brightness InGaN LED provides blue light and green light, with the wavelength range of 450-480nm for blue light, 500nm for blue-green light, and 520nm for green light. Its lumen efficiency is 3- 15 1m/w, and the lumen efficiency of ultra-high brightness LED has surpassed that of incandescent lamp with filter, which can replace incandescent lamp with power within 1w, and LED array can replace incandescent lamp with power within 150w.

4. What are the basic simple common sense 4. LED display maintenance?

There are four main maintenance methods for LED display screen: inspection, cleaning, fastening and surface cleaning of the display screen.

First patrol the LED display body for maintenance, the LED display control system for maintenance, and the LED display specially plays operating software. For outdoor LED display, the damage caused by natural factors such as wind, rain, thunder and electricity is not covered by the warranty. Secondly, the cleaning dust will still fall on the surface of the internal control device of the display screen, which will reduce the thermal conductivity and insulation performance. In wet weather, the dust will absorb the moisture in the air and cause a short circuit. It will also lead to the long-term mildew of PCB and electronic components, which will lead to the decline of equipment technical performance and failure. Therefore, the cleaning of LED display screen seems simple, but it is actually a very important link in maintenance.

Thirdly, the fastening signal terminal will also loosen due to the cold and hot changes of the ambient temperature, and the moisture erosion will lead to poor contact and equipment failure. Therefore, the connector of LED display screen must be tightened regularly. When adjusting fasteners, the strength should be even and appropriate to ensure firmness and effectiveness.

There are two points to be noted in the preparation for cleaning the display surface: first, before cleaning, the power cord needs to be * * *; The second is the choice of cleaning solution, which generally includes electrolyte, high-purity distilled water and antistatic liquid. .

5.5 What should I pay attention to in daily maintenance? Led display?

Daily maintenance methods of Led display screen 1. The power supply is stable and the grounding protection is good.

2. Do not use it in harsh natural conditions, such as strong lightning weather. 3. Prevent water, iron powder and dust from damaging the circuit in the screen.

4. Cut off the power supply after entering the water until the unit board in the screen body is dry. 5. Switch sequence is 5. LED display: Turn on the screen first, then turn it on, then turn it off.

6. Wipe the surface with alcohol, or use a brush or vacuum cleaner to remove dust. 7. Rest time ≥2 hours/day, at least 1 time/week in rainy season and at least 2 hours/month in normal times.

8. Check the circuit regularly. If it is damaged, please repair or replace it. 9. Don't play in all-bright pictures such as all-white, all-red, all-green and all-blue for a long time, so as to avoid overheating of the power cord due to excessive current, damaging the LED lights and affecting the service life of the display screen.

10. Do not disassemble or splice the screen at will. 1 1. The main control computer and other related equipment should be placed in an air-conditioned and dusty room to ensure the ventilation, heat dissipation and stable work of the computer.

12. Non-professionals are forbidden to touch the internal lines of the display screen to avoid electric shock or line damage.

What is the method of 6.6? LED display synchronization?

Multimedia method, usually called synchronous screen method.

This method uses ordinary multimedia card to collect TV signals, and carries out demodulation, filtering and timbre separation. After A/D conversion, the image signal is encoded and compressed by MPEG and stored.

Decompress when playing and watch it directly on the computer monitor. The signal sent to the LED screen is obtained from the computer's DVI interface or graphics card through a special interface card, which needs some processing.

At this time, the LED large screen is actually equivalent to the computer display or a part of it, usually called a window, which can realize one-to-one synchronous display. Because the computer monitor scans line by line, if the display signal has not been processed by frame extraction and line extraction, the display format of the big screen is the display format.

For example, VGA format is a progressive scanning format with 640x480 pixels, and its scanning update rate is 75Hz. By the way, the situation of non-video programs is relatively simple. Although some game animations also require good continuity, it is acceptable that the screen update rate exceeds 10Hz for animations played on a large screen.

If the signal transmission problem is well solved in the process of using LED display screen, the content of LED display screen function can be guaranteed to be displayed normally and synchronously. The engineering team should be equipped with appropriate signal transmission equipment and control system according to the requirements of the application area.

It also needs the joint efforts of technicians in the industry to develop and design signal transmission equipment with higher performance to meet the market demand. .

What are the main knowledge of 7.7? LED display?

I. Classification and classification method of LED display screen Description of using environment Indoor LED display screen Indoor LED display screen is used in indoor environment. This kind of display screen has moderate brightness, large viewing angle, short color mixing distance, light weight and high density, and is suitable for close viewing.

Outdoor LED display Outdoor LED display is used in outdoor environment. This display has high brightness, long mixing distance, high protection level, strong waterproof and ultraviolet resistance, and is suitable for long-distance viewing. Display color Monochrome LED display screen Monochrome LED display screen consists of LED lights of one color, which can only display a single color, such as red, green and orange.

Two-color LED display The two-color LED display consists of red and green LED lights, and the two-color display with 256 gray levels can display 65,536 colors (the two-color display can display red, green and Huang San colors). Full-color LED display The full-color LED display consists of red, green and blue LED lights, which can display white balance and 16,777,216 colors.

Display function graphic LED display screen (asynchronous screen) The graphic LED display screen can display information such as text, graphics and pictures. Can be displayed online and offline.

Video LED display screen (synchronous screen) Video LED display screen can display all kinds of information synchronously in real time, such as 2D or 3D animation, video, TV, DVD, live broadcast and so on. 2. The basic structure of 2.LED display screen 1. Asynchronous screen: generally composed of display unit board (module), bar screen card, switching power supply and HUB board (optional).

Connect with the computer through serial port, change the displayed text, and then disconnect from the computer. 2. Synchronization screen: The synchronization screen system is complex, and the system can be large or small. Generally, it consists of computer, DVI graphics card, data sending card, synchronous data receiving card, HUB board, network cable and LED display screen.

The system always needs an online computer to work, and the images and characters on the computer are displayed on the LED screen. 3. The noun concept involved in 3.LED display screen is 1. Pixel is the smallest imaging unit of LED display screen.

Commonly known as "dot" or "pixel point". The above picture is 1 display pixel composed of 2 red and 2 green. 2. Display module: the smallest unit consisting of several display pixels, which independently forms an LED display screen in structure.

Indoor screen adopts 8×8 display modules, that is, each display module has 64 pixels. The outdoor screen uses a single light bulb, usually consisting of 1-3 light bulbs of the same or different colors to form a pixel of the module. As shown in the picture on the right, the outdoor screen module consists of two red light bulbs, and the display pixel is 1 3. Display module: an independent unit determined by the circuit and installation structure, which has the display function and constitutes the LED display screen.

Simply put, for the convenience of assembly and display, semi-finished products are usually provided in the form of display modules, combined with display drivers. Indoor screen is commonly known as "unit board"; Outdoor screens are commonly called "modules", and then several modules are combined with chassis, fan and power supply to form a "box", which is mostly used for large full-color screens.

Generally, there are 64x32(64 columns and 32 rows, composed of 32 modules), 64x 16(64 columns 16 rows, composed of 16 modules) and so on. The following figure shows a 64x 16 cell board: the front of the indoor screen cell board and the back of the indoor screen cell board. The outdoor screen modules usually have 64x32, 32x32, 32x 16,16, 16x8. The above picture shows 16x8(2 red

When used outdoors, the waterproof structure is added, and we can see the plastic shell. The plan view of its overall structure is on the far right: the lamp beads are inserted on the display board, and the display driving circuit is on the back board, which is a split structure, and some of them are integrated structures in which the display board and the display driving circuit are made on a circuit board. We can see the difference from the following two pictures. In fact, the front panel and the back shell are just a plastic shell. There are holes corresponding to the lamp beads on the panel, so that the lamp beads can leak from the machine head, and there are screw holes or magnetic columns for installation on the back shell, which makes the module easy to assemble.

The front of the module is filled with a special waterproof glue for display screen. Front of outdoor screen module Back of outdoor screen module Back of outdoor screen module (display panel and driving panel are separated) (display panel and driving panel are integrated) The box used for large outdoor full-color screen usually consists of several modules+chassis+fan+power supply. 4.LED display screen body: the unit boards/modules/boxes are spliced together in a certain way, and the control card/control system, power supply and frame are added to form an LED display screen.

Indoor screen: display unit board+control card+power supply+aluminum frame outdoor screen: display module+control card+power supply+aluminum frame full-color screen: display box+control system+computer+communication network+frame, etc. 5. Point distance: it is the distance between two pixel points. Mainly depends on the distance of the viewer.

Generally, the concept of point distance is used for outdoor screens, such as P6, P7.62, P8, P 10, P 12, P 16, P20, etc. , in millimeters and millimeters. The viewing distance of outdoor screen is generally within 30m, and the module is not more than P 16( 16mm).

The denser the dot spacing, the thinner the displayed strokes, the more pixels per unit area and the more expensive the display screen. 6. Scanning mode: Outdoor screen modules usually have scanning mode problems.

The scanning mode determines the connection form between modules, including116, 1/8, 1/4, 1/2 and static. Because the LED display screen is refreshed line by line, the scanning mode also determines the display refresh mode. For example, 1 16 is a refresh1line, and16 is a scanning period, which needs four ABCD signals to control; 1/8 means that 1 line is refreshed every time, and 8 is a scanning period, which needs three ABC signals to control; Others and so on.

If the same LED lamp is used, the scanning brightness of116 is lower than that of 1/8, and the static brightness (11) is the highest. Indoor screens are generally scanned by116, and outdoor and semi-outdoor screens are generally scanned by116 or 1/8.

It is best to scan with 1/4 in the environment where the screen is often exposed to fierce sunlight. Scan mode routing description diagram116 (116) Scan 16.0: straight line with16 rows of data.

1/8 (1/8) Scan 8.0: straight line, with 8 lines in one data band. 8. 1: hanging snake, 16 line, 8 line folding.

8.2: Drop the snake, 16 line, 8 line folding. 1/4 (quarter) scanning 4.0: straight line, one data band with 4 lines.

4. 1: There are several ways to go up in a snake.