|Design and selection of full color LED display video walls|
1. The size of the display is designed to have three important factors when designing the screen size:
(1) the need to display content;
(2) Space conditions of the venue;
(3) Display unit template size (indoor screen) or pixel size (outdoor screen).
2. Power consumption and power requirements
The power consumption of the display is divided into average power consumption and maximum power consumption. The average power consumption, also known as the working power, is the actual actual power consumption. The maximum power consumption is the power consumption during extreme conditions such as startup or full brightness. The maximum power consumption is an essential factor for AC power supply (wire diameter, switch, etc.). The average power consumption is generally 1/3 of the maximum power consumption.
The display is a large-scale precision electronic device. For safe use and operation, the AC220V power input or the AC220V power input of the computer connected to it must be grounded.
Note: The AC220V power input ground of the computer is connected to the computer case.
3. Outdoor screen should consider the problem
The main problems of the outdoor screen are as follows:
(1) The display screen is installed outdoors, often exposed to the sun and rain, the wind blows the dust cover, and the working environment is bad. If the electronic equipment is wet or seriously damp, it may cause a short circuit or even a fire, causing malfunction or even fire, resulting in loss;
(2) The display screen may be attacked by strong electric power caused by lightning;
(3) The ambient temperature varies greatly. When the display is working, it must generate a certain amount of heat. If the ambient temperature is too high and the heat dissipation is poor, the integrated circuit may not work properly or even be burned, so that the display system cannot work normally;
(4) The audience is wide, the distance between the vision is long, the field of vision is wide, and the ambient light varies greatly, especially in direct sunlight.
In response to the above special requirements, the outdoor display must:
(1) The joint between the screen body and the screen body and the building must be strictly waterproof and leakproof; the screen body should have good drainage measures, and the water can be discharged smoothly once the water accumulation occurs;
(2) Install lightning protection devices on the display screen and buildings. The main body and the outer casing of the display are well grounded, and the grounding resistance is less than 3 ohms, so that the large current caused by lightning is discharged in time;
(3) Install the ventilation equipment to cool down, so that the internal temperature of the screen is between -10 °C and 40 °C. An axial fan is installed on the back of the screen body to discharge heat;
(4) Select an industrial-grade integrated circuit chip with a working temperature between -40 ° C and 80 ° C to prevent the display from starting due to low temperature in winter. ;
(5) In order to ensure long-distance visibility under strong ambient light conditions, ultra-high brightness LEDs must be used;
(6) The display medium adopts a new wide viewing angle tube with wide viewing angle, pure color, consistent coordination, and a service life of more than 100,000 hours. The outer packaging of the display medium is currently the most popular square-shaped cylinder with a cover, sealed by silicone, and metal-free assembly; its appearance is exquisite and beautiful, durable and durable, with direct sunlight, dustproof, waterproof, high temperature resistance, and short circuit protection. "Five defenses" features.
Frequently Asked Questions
1. What are the factors that take into account the screen area allowed by the user's site?
(1) The relationship between the effective line of sight and the actual site size;
(2) pixel size and resolution;
(3) The unit is the base area estimate;
(4) Screen body mechanical installation and maintenance operation space;
(5) The influence of the screen tilt angle on the distance.
2 What are the playback effects that users need?
(1) Text display: depending on the size of the text and the need for resolution;
(2) Ordinary video display: 320 × 240 dot matrix;
(3) Digital standard DVD display: ≥ 640 × 480 dot matrix;
(4) Complete computer video: ≥800×600 dot matrix;
3 What are the brightness requirements for the screen brightness?
The general brightness requirements are as follows:
(1) Indoor: >800CD/M2
(2) Semi-indoor: >2000CD/M2
(3) Outdoor (sitting south to north): >4000CD/M2
(4) Outdoor (sitting north facing south): >8000CD/M2
4 What kind of brightness requirements do red, green and blue have in terms of white composition?
Red, green, and blue contribute differently in terms of white color. The root cause is that the retina of the human eye is different for different wavelengths of light. After a large number of experimental tests, the following approximate ratios are obtained for reference design:
The ratio of simple red, green and blue is: 3:6:1vGD-
The exact red, green and blue brightness ratio is: 3.0:5.9:1.1
5. Why use a pure green tube for high-end full-color displays?
In the actual P3.91 LED display production, you should choose a three-color light tube with high luminous efficiency and rich color rendering to make the color triangle area in the chromaticity diagram It is possible to have a near-tongue spectral curve to satisfy a rich color and emit sufficient brightness while the tip of the tongue curve is 515 nm wavelength light, so high-end LED tubes.
6. How to determine the brightness of a single tube of a computer under the conditions of brightness and dot density?
The calculation method is as follows: (taking two red, one green, one blue as an example)
Red LED light brightness: brightness (CD) / M2 ÷ points / M2 × 0.3 ÷ 2
Green LED brightness: brightness (CD) / M2 ÷ points / M2 × 0.6
Blue LED brightness: brightness (CD) / M2 ÷ points / M2 × 0.1
For example: 2500 points per square meter, 2R1G1B, brightness requirement per square meter is 5000 CD/M2, then:
The brightness of the red LED is: 5000÷2500×0.3÷2=0.3
The brightness of the green LED is: 5000÷2500×0.6÷2=1.2
The brightness of the blue LED is: 5000÷2500×0.1=0.2
The brightness per pixel is: 0.3×2+1.2+0.2=2.0 CD
7. Why use the DVI display interface standard?
(1) The DVI display card interface is a display interface that conforms to the international standard of the computer;
(2) Easy to install without opening the case;
(3) High memory and strong dynamic display capability;
(4) Strong compatibility between software and hardware;
(5) Support all operating systems and application software, display flexible and convenient;
(6) Mass production, low cost and easy maintenance.
8. Can the display be controlled by a notebook, and why?
No. The graphics card of the notebook computer is built-in and cannot be connected to the control system. At present, BOE has a notebook with a DVI interface, which can realize notebook control.
9. What is the difference between using full-color screens and using Japanese-made tubes to eliminate prices?
(1) Die: Nichia Company independently produces the die, and the domestic pipe generally uses the die of the US or Taiwan company;
(2) Packaging: Nichia has its own packaging, no domestic production plants, and more domestic tube packaging manufacturers;
(3) Consistency: The wavelength difference between the Japanese and Asian tubes is small, the consistency is good, and the consistency of domestic tubes is relatively poor;
(4) Service life: The service life of the Japanese pipe is relatively long, and the attenuation of the domestic pipe is relatively serious;
10. What is the difference between an indoor module full color screen and a patch full color screen?
(1) Light-emitting part: The display module of the module full-color screen is generally yellow-green, and the module of pure green is more expensive; the full-color screen of the patch generally uses a pure green die;
(2) Display effect: the pixel of the full color screen of the module has a relatively thick visual sense, low brightness, and easy mosaic phenomenon; the patch full color screen has good consistency and high brightness;
(3) Maintenance: The module is not easy to maintain in full color, and the replacement cost of the whole module is high; the patch is full color and easy to maintain, and the single lamp can be repaired and replaced;
11. Can the outdoor screen use the surface mount LED, why?
No. The outdoor screen installation structure is strict, and the patch LED cannot adapt to the harsh environment of the outdoor;
The brightness of the outdoor screen is relatively high. Currently, the patch LED cannot meet the brightness requirements of the outdoor screen.
12. Why is the production cycle of outdoor screens longer?
(1) Raw material procurement: LED lamp purchase cycle is long, especially imported die, ordering period needs 4-6 weeks;
(2) Complicated production process: PCB design, shell production, glue filling, whitening balance, etc.;
(3) Strict structural requirements: generally designed for the cabinet, wind, rain and lightning protection should be considered.
13. How to help users choose the right display?
(1) the need to display content;
(2) Confirmation of visual distance and viewing angle;
(3) the requirements of the screen resolution;
(4) Requirements for the installation environment;
(5) Cost control;
14. What is the general aspect ratio of the display?
Graphic screen: determined according to the displayed content;
Video screen: generally 4:3 or close to 4:3; ideal ratio is 16:9.
15. What is the number of points that a control system can control?
Communication screen A card: monochrome, two-color 1024×64
Communication screen B card: monochrome: 896 × 512 two colors: 896 × 256
Two-color screen: 1280×768
Full color screen: 1024×512
16. Display installation requirements?
Power supply requirements: The power supply connection point should be 220V mains power supply within the screen size, the fire line 0 line ground line; 380V mains power supply, three fire line and 0 line grounding line; the cross line area of the live line and the 0 line wire are the same;
The display of 10 kW or more should be equipped with a step-down starting device.
Communication requirements: Communication distance is defined by the length of the communication line.
The communication line should be installed with the communication line length standard used for the model of the installed display.
The communication line is prohibited from being routed in the same line as the power line.
Installation requirements: the display is installed horizontally and horizontally. It is not allowed to install the upper and lower adjustment rods for the rear tilting. The front and the bottom of the installation should be installed.