With the advancement of full-color LED display technology, the dot pitch is becoming smaller and smaller. Small-pitch LED products have become well-deserved star products, and their market applications are rapidly expanding. According to the industry consensus, a full-color LED display with a dot pitch of less than 2.5mm is a small-pitch LED display. Usually choose a small-pitch full-color LED display, which can be considered from the following aspects:
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Pay attention to the following aspects in the selection and use of the small-pitch full-color LED display:
1. The filling factor should be high
The fill factor (FillFactor) of a full-color LED display is also known as the ratio of the bright area, that is, the ratio of the light-emitting area of each pixel to the physical surface area occupied by the pixel. The full-color LED display is made up of discrete pixels, and there are obvious non-luminous black areas between the pixels. When viewed at close range, the picture is inconsistent and incomplete, and uneven brightness produces graininess. If the light-emitting source is limited to a small pixel surface area, so that the brightness of a single pixel is several times or even ten times the brightness of the entire screen, it will Causes a more serious glare. The TCO'99 standard recognized by the flat panel display industry stipulates that the fill factor should not be less than 50 percent . At present, the fill factor of many full-color LED displays on the market does not meet this indicator. The cut-off characteristic of the TV's low-pass filter also directly affects the appropriate shooting distance of the full-color LED display with different fill factors.
A full-color LED display with the same dot pitch has more attenuation than a large filling factor, so the shooting distance needs to be increased. If the system low-pass filter passband is 4MHz and the high-frequency attenuation characteristic is 12db/octave, then the shooting distance with a fill factor of 25 percent will attenuate 1.15db more than that with a fill factor of 50 percent , and the shooting distance needs to be increased by about 10 percent . The improvement of the fill factor makes the viewing angle of the full-color LED display wider and the color mixing effect is more ideal, which overcomes the glare of the pixels, and also creates conditions for appropriately increasing the brightness of the entire screen to obtain better results.
2. The color temperature can be adjusted
Color Temperature (ColorTemperature) is the temperature determined by comparing the shape of the emission spectrum of the emitter with the shape of the best-fit blackbody emission spectrum. When a full-color LED display is used as a background in a studio, its color temperature should be consistent with the color temperature of the lights in the studio, so that accurate color reproduction can be obtained during shooting. According to the needs of the program, the studio lighting sometimes uses 3200K low color temperature lamps, sometimes 5600K high color temperature lamps, and the LED display needs to be adjusted to the corresponding color temperature to obtain satisfactory shooting results.
3. The shooting distance should be appropriate
As mentioned in the previous discussion of dot pitch and filling factor, the appropriate shooting distance for full-color LED displays with different dot pitches and different filling factors is different. The distance between the person being photographed and the screen is more suitable to be 4-10 meters, so that you can get a better background picture when shooting people. If the person is too close to the screen, when shooting close-up shots, the background will appear grainy, and it is easy to produce moiré interference.
4. Ensure a good use environment
During the service life of the product, the failure rate is low only under suitable working conditions. As an integrated electronic product, the full-color LED display is mainly composed of a control board equipped with electronic components, a switching power supply, and a light-emitting device. The life and stability of all these components are closely related to the operating temperature. If the actual working temperature exceeds the specified use range of the product, not only its life span will be shortened, but the product itself will also be severely damaged. In addition, the threat of dust cannot be ignored. Working in a dusty environment, because the PCB absorbs dust, and the deposition of dust will affect the heat dissipation of the electronic components, which will cause the temperature of the components to rise, and then the thermal stability will decrease or even cause electric leakage, which can lead to burns in severe cases. Dust will also absorb moisture, which will corrode electronic circuits and cause short-circuit problems that are not easy to troubleshoot. Pay attention to keeping the studio clean.
The renovation of the studio will generate a lot of dust, so it is necessary to protect the full-color LED display in advance.
Then, when purchasing small-pitch LED products, what are the key points that users should pay attention to in order to maximize the investment benefits while meeting the needs of use?
1. "Low brightness and high gray" is the premise:
As a display terminal, a small-pitch full-color LED display must first ensure the comfort of viewing. Therefore, when purchasing, the primary concern is the brightness issue. Relevant studies have shown that, in terms of human eye sensitivity, LED as an active light source has twice the brightness of passive light sources (projectors and liquid crystal displays). To ensure the comfort of human eyes, small-pitch full-color LEDs The brightness range of the display can only be between 100cd/m2-300 cd/m2.
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However, in the traditional full-color LED display technology, reducing the brightness of the screen will cause the loss of grayscale, and the loss of grayscale will directly affect the picture quality. Therefore, an important judgment for high-quality small-pitch full-color LED display The standard is to achieve "low brightness and high gray" technical indicators. In actual purchase, users can follow the principle of "the more brightness levels that can be recognized by the human eye, the better". The brightness level refers to the brightness level of the image that the human eye can distinguish from the darkest to the whitest. The more the recognized brightness level, the larger the color gamut space of the display screen, and the greater the potential for displaying rich colors.
2. When choosing the point spacing, pay attention to the balance of "effect and technology"
Compared with the traditional LED screen, the outstanding feature of the small-pitch full-color LED display is the smaller dot pitch. In practical applications, the smaller the dot pitch, the higher the pixel density, the more information capacity per unit area can be displayed at one time, and the closer the distance suitable for viewing. On the contrary, the longer the distance suitable for viewing. Many users naturally think that the smaller the dot pitch of the product, the better. However, this is not the case.
Conventional LED screens want to achieve the best visual effects and have the best viewing distance, and the same is true for small{{0}}pitch full-color LED displays. Users can make simple calculations through the best viewing distance=dot spacing/0.30.8. For example, the best viewing distance of the P2 small-pitch LED screen is about 6 meters away.
We know that the smaller the dot pitch, the higher the cost of the small-pitch full-color LED display. Therefore, in actual purchase, users must comprehensively consider their own cost, demand, application range and other factors.
3. When choosing the resolution, pay attention to the match with the "front-end signal transmission equipment"
The smaller the dot pitch of the small-pitch full-color LED display, the higher the resolution, and the higher the picture clarity. In actual operation, users want to build the best small-pitch LED display system. While paying attention to the resolution of the screen itself, they must also consider the combination of it and the front-end signal transmission product.
For example, in security monitoring applications, the front-end monitoring system generally includes video signals in D1, H.264, 720P, 1080I, 1080P and other formats. However, not all small-pitch full-color LED displays on the market can It supports video signals in the above formats. Therefore, in order to avoid waste of resources, users must choose according to their needs when purchasing small-pitch full-color LED displays, and avoid blindly following the trend.
At present, small-pitch full-color LED display products have been widely used in TV studios, power system monitoring centers, aerospace command centers, military command centers, government halls, urban monitoring centers, video conference rooms, dispatching rooms, airports, railway stations , Hotels and large and medium-sized enterprises.
