How much do you know about LED display and DLP splicing screen?
TV programs are becoming more and more colorful and interactive, and the visual impact on viewers is also increasing. The background of the programs plays an important role. In recent years, LED displays and DLP splicing screens have gradually become the mainstream of the program background. This article intends to do some analysis and discussion on the technical characteristics, use effects, advantages and disadvantages, and precautions of these two displays.
First, the LED display
LED is the abbreviation of Light Emitting Diode, which means light-emitting diode, which is a solid-state semiconductor device that can directly convert electrical energy into light energy. LED display is an advanced digital information product. It successfully integrates computer technology, network communication technology, image processing technology, embedded control technology, etc., has a flexible display area and resolution (modular can be arbitrarily assembled), high Brightness, low power consumption, long life, low heat, environmental protection and durability, and the comprehensive use of sound, light, electricity, graphics, text, is a comprehensive and perfect display of information terminal products.
LED displays are increasingly used in large-scale events in TV studios and TV broadcasts. As a stage background, it provides a variety of vivid and dazzling background pictures and more interactive functions, making the background picture dynamic and still. , Make the performance and the background into one, make people feel immersive. It gives a greater space for imagination, designing a modern and visually impactful stage, perfectly integrating the atmosphere of the scene and the show, and achieving functions and effects that are difficult to achieve by other stage art equipment.
The audience's viewing effect and feeling on the LED display is very intuitive. As long as the screen size and pixel pitch and viewing distance are appropriate, this direct-view display can obtain excellent results. However, the number of viewers in front of the TV is much larger than the number of live viewers. Therefore, the viewing effect of the viewers in front of the TV is the focus of research and discussion by TV technicians. Many stations use LED displays, but the effects of the TV pictures are very different. Some are colorful, clear and stable from beginning to end. Some are small and indistinct when the picture is in the long-distance view. The erratic streak interference, in some close-up shots of the character, often appears in the moire interference, disturbing the audience's sight.
Pay attention to the following aspects in the selection and use of LED display:
1. Dot spacing should be as small as possible
Dot pitch is the distance between the center points of adjacent pixels of the LED display. The smaller the dot pitch, the more pixels per unit area, the higher the resolution, the closer the shooting distance can be, and of course the more expensive it is. At present, the dot pitch of LED display screens used in domestic TV studios is mostly 6-8 mm. In order to achieve excellent results, we must carefully study the relationship between the resolution of the signal source and the dot pitch, and strive to achieve consistent resolution. Achieve point-to-point display for best results.
2. Higher fill factor
The fill factor of the LED display screen (Fill Factor) is also called the bright area ratio, that is, the ratio of the light emitting area of each pixel to the physical surface area occupied by the pixel. LED display screens are arranged by discrete pixels, and there are obvious non-luminous black areas between the pixels. When viewed from a close distance, the picture is incoherent and incomplete, and the uneven brightness produces a grainy feeling. If the light source is confined to a small pixel surface area, causing the brightness of a single pixel to be several times or even ten times the brightness of the entire screen, Causes a more severe glare. The TCO’99 standard recognized by the flat panel display industry stipulates that the fill factor should not be less than 50%. At present, the fill factor of many LED display screens on the market has not reached this index. The cut-off characteristic of the TV's low-pass filter also directly affects the appropriate shooting distance of LED displays with different fill factors.
For LED displays with the same dot pitch, the smaller the fill factor is, the greater the attenuation of the fill factor is, so the shooting distance needs to be increased. If the low-pass filtering passband of the system is 4MHz, and the high-frequency attenuation characteristic is 12db / octave, then the shooting distance with a fill factor of 25% is attenuated 1.15db more than that with a fill factor of 50%, and the shooting distance needs to be increased by about 10% . The increase of the fill factor makes the display screen's viewing angle wider and the color mixing effect more ideal. It overcomes the glare problem of the pixels and also creates conditions for properly increasing the brightness of the entire screen to obtain better results.
3.Color temperature can be adjusted
ColorTemperature is the temperature determined by comparing the shape of the emission spectrum of the emitter with the shape of the best fit black body emission spectrum. When a studio uses an LED display as the background, its color temperature should be consistent with the color temperature of the lights in the studio to get accurate color reproduction during shooting. According to the needs of the program, the studio lighting sometimes uses 3200K low color temperature lamps and sometimes 5600K high color temperature lamps. The LED display needs to be adjusted to the corresponding color temperature to obtain satisfactory shooting results.
4. The shooting distance should be appropriate
As mentioned earlier when talking about dot pitch and fill factor, the appropriate shooting distance for LED displays with different dot pitch and different fill factor is different. The distance between the person being photographed and the screen is more suitable at 4-10 meters, so that you can get a better background picture when shooting people. If the person is too close to the screen, the background will appear grainy when shooting close-ups, and it is also prone to moiré interference.
5. Ensure a good use environment
The failure rate of the product is only low under the proper working conditions during the service life. As an integrated electronic product, the LED display is mainly composed of a control board, switching power supply, light-emitting device, etc. with electronic components, and 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 will be shortened, but the product itself will also be severely damaged. In addition, the threat of dust cannot be ignored. Working in a relatively dusty environment, because the PCB absorbs dust, and the deposition of dust will affect the heat dissipation of electronic components, which will cause the component temperature to rise, and then there will be a decrease in thermal stability and even leakage, which will cause burnout in severe cases. Dust also absorbs moisture, which can corrode electronic circuits and cause some short-circuit problems that are not easy to troubleshoot. Pay attention to keeping the studio clean. Studio reconstruction will generate a lot of dust, and LED screens need to be protected in advance.
The use of the LED display screen greatly enriches the display of the program background. The LED display screen is used as the background, which is suitable for large-scale variety shows in large scenes and studios.
Second, DLP splicing screen
DLP is the abbreviation of Digital Light Processing, which means digital light processing. This technology is to digitally process the image signal and then project the light. From the technical principle of DLP, it has the advantages of minimal signal noise, accurate gray level, high reflectivity, seamless image display, and high reliability. DLP splicing screen is made by splicing multiple rear-projection display units. Its main feature is that the stitching is small and can be controlled to within 0.5 mm, which is also beyond the other two major LCD and PDP technologies. Due to its advantages, in recent years, TV stations have popularly used DLP splicing screens as backgrounds for studios. CNN, BBC, SKY and other well-known large TV stations have achieved excellent program results after use.
DLP splicing screens also have disadvantages. Because the light source of DLP splicing comes from the light bulb, it causes large power consumption and high heat dissipation, and the brightness will decrease after a period of use. The user must constantly replace the light bulb to maintain the original display effect. With the development of technology, thanks to the addition of LED light sources, the current DLP splicing screen has solved a series of problems such as frequent lamp replacement, large power consumption, and high heat dissipation. After adopting the LED light source, the DLP splicing screen has not only achieved a major breakthrough in service life and power consumption, but also has a revolutionary change in color, so that the DLP splicing screen continues to maintain the market-leading advantage.
If you want to know more, our website has product specifications for the LED display and DLP splicing screen, you can go to ALLICDATA ELECTRONICS LIMITED to get more information