In order to quickly determine the quality of the led display is good or bad, from the parties point of view of the integrated display led the following nine important projects. In front of eight projects for the general led display, the first nine items for the small pitch led display.
Maximum brightness
Refers to a certain ambient illumination, led display the primary color in the highest gray level, the highest brightness when the brightness. In short, the use of software to set the display for the white 255 when using the light gun in the direction of the normal measured brightness.
For the outdoor led display according to the use of the environment, the maximum brightness will have different requirements, because the ambient light is relatively strong occasions, the requirements led display brightness is higher, in order to let the masses see the screen display the content. Under normal circumstances, the display sitting south to the north of the maximum brightness requirements, as long as the 4000CD / m2 will be able to meet the requirements, and sitting south of the screen requires the whole screen brightness can reach 7000CD / m2, east and west South of the requirements are the same, because there will be part of the time the sun will be directly exposed to the led display. The theoretical brightness requirements greater than 5500CD square meters brightness is enough.
Color temperature
When we see the image on the screen with the material inconsistent or different, when our picture is seriously distorted, which is related to the color of the white color display led white, if the human eye directly watch the display of its white balance Of the color temperature between 6500 to 8000K more appropriate, and if the TV broadcast used by the display, the screen body color temperature should be adjusted to about 5500K or so, so that after the video recording through the camera after the display screen is true The
Refresh rate
Refresh rate refers to the led display shows the number of times the message is displayed every second. Refresh the frequency is too low, the human eye to watch the LED display will be jitter phenomenon, usually we use the camera to shoot will see the scan line appears. Usually the human eye on the refresh rate requirements for more than 300Hz, that is, refresh rate as long as more than 300Hz, with the naked eye to watch the display will not have the feeling of jitter, and if you use the camera to shoot according to the different settings of different cameras, 600Hz or more to capture the scan line. High refresh can improve the brightness and color effects of the display. With a digital camera can be detected, if it is a high refresh, the camera shot the picture is very clear, no snow and scanning lines. This indicator is particularly important when renting screens and televisions.
Wavelength
Wavelength determines whether the color is pure and the color is consistent. Resolution method is very simple; if there is no professional equipment, how to use eyes to distinguish?
First: the whole screen to play white, the screen should be pure white, without any other variegated. If you think there is a little red or blue, to prove that the display material and process quality control and so have a problem. Use a long time, will become more and more serious.
Second: hit the red, green, blue monochrome, the central wavelength of the color is usually we are talking about the red is green, if the deep or slightly lighter color, proved to be partial wavelength. If a color is inconsistent, proved that the wave is too large, high-quality display in the range of the central wavelength, blue and green wave control at 3nm, red wave is less than 5nm.
The angle of the LED
The luminous view of the luminous tube refers to the viewing direction of the brightness down to the led display normal direction of the brightness of one-half, the same plane two observation direction and the direction of the normal direction of the angle. Divided into horizontal and vertical viewing angles.
For outdoor LED advertising display generally use elliptical LED or patch LED, oval LED with a small angle, high brightness characteristics, and patch LED vertical angle is much larger than the elliptical tube, but its brightness is less than the elliptical LED , From the user's point of view should be based on the led display of the audience and the surrounding light environment to choose different angles of the LED. For indoor LED display because of its low brightness requirements, the audience is generally broader, so the patch LED is the best choice. It should be noted that the market is now part of the LED manufacturers to reduce costs, confuse the user, the luminous tube brightness is relatively high, and the perspective of doing more than the conventional light tube angle, which will lead to led display Positive to see the brightness is very high, but the side of the relatively large angle to see the image can not see the situation. Small size LED chip in order to improve the brightness, usually a small angle of the package. Large size does not require small angle packaging, because it does not need that high brightness. So, large angle (110) high brightness low current is the best.
Circuit design section
Circuit board design and materials on the stability of the led display and display the role of a crucial role. Mainly in the following areas:
Material: FR-4 glass fiberboard, some manufacturers in order to reduce the cost may use FR-2 paper substrate; copper foil thickness: the thickness of the copper foil, the thickness of the copper foil, the thickness of the copper foil, the thickness of the copper foil, On the PCB board cooling and line stability has a role can not be ignored, the normal copper foil thickness is 35um (1Oz), and some manufacturers will use 18um (0.5Oz) copper foil thickness to shoddy; then as a consumer How can you identify it? You can take an empty PCB by weight to distinguish, under normal circumstances, the heavier the better.
2, the design of several key points: connectors, connectors refer to the module and the module between the connector, and now the market is more than the main two, one is the horns, one is the row needle. The advantages of horns are through the two card bit to catch the cable, not prone to problems caused by the connector problems; electrolytic capacitors and tantalum capacitors on the choice of long life requirements, tantalum capacitors is undoubtedly the first choice for Requires low-cost occasions, electrolytic capacitors are preferred.
Automated production equipment
Led display most of the electronic components inside, and static electricity on the electronic components have a great harm, and sometimes electrostatic breakdown of the components directly to damage, and sometimes it does not directly breakdown, but leave hidden dangers, the side effects Is the use of components after a period of time to damage. In the electronics manufacturing industry, for the handling of artificial static people think of a lot of ways, including wearing static ring, wearing a static clothing, the use of clean room and so on. In fact, the most effective way is to try to avoid the staff to contact electronic components, and the use of automated equipment to achieve this purpose.
Average power consumption
Square power consumption is a square meter area led display produced by the power consumption, we usually say that the unit of electricity for the tile / hour. Such as a square meter led display power consumption is 300 watts, then the display of each square meter per hour will consume 300 watts / hour of electricity, that is, we often say that 0.3 power. Led display power consumption will generally have two indicators, one is the maximum power consumption, one is the use of power consumption. The maximum power consumption is the maximum brightness of the led display when the power consumption, how to use the eyes to determine the size of the maximum power consumption? Method is very simple: see the number of power behind the box, multiplied by the maximum power of each power, according to the box Size can calculate the maximum power consumption square meters, the general use of the power supply has two, 200W and 300W power supply.
Indoor small spacing: low light high ash
Low brightness, the specific explanation: small distance led display brightness range of 100 cd / O-300 cd / O interval, the display of the gray scale does not lose, or the degree of gray loss in the human eye is difficult to detect Within range.
Low light will be a small distance between the small led display product quality and quality of one of the key factors. For small pitch products, led display contest will no longer be compared with someone who is high brightness, but rather who is low brightness Than anyone else's display screen can be done to reduce the brightness while not losing the grayscale and quality. In other words, only to do a low light high-gray small distance led display is in line with user requirements, with a competitive strength of the good product.
The human eye in the dark environment below, close, long time to watch the high brightness of the small distance led display, LED-specific high brightness often makes people feel dazzling, and even cause eye pain, tear and vision decreased. Therefore, led display brightness is too high, will give the indoor application of the user to bring visual fatigue, and even serious may cause irreparable damage to the human eye! Can be said that the small distance led display brightness is definitely not the higher the better, The brightness down. A large number of tests show that the brightness of the led display control in the 100 cd / O-300 cd / O this brightness range, the human eye is more comfortable feeling.
But not directly adjust the brightness of the display can solve this problem. Because the conventional led display has a low light low gray features, that is to say when the display brightness will be accompanied by the loss of the screen gray.