What’s 5 purpose of functional analysis for SMD Screen devices used in outdoor?
Performance analysis of dedicated SMD devices for outdoor full-color SMD displays.
Overview
LED display screens have occupied the mainstream market of large-sized indoor and outdoor displays with their high brightness, weather resistance, and large size.
While picture tube displays (CRT), liquid crystal displays (LCD) and plasma displays (PDP) have become popular in small and medium-sized, indoor and near Distance viewing displays dominate the market. LED display screens have been widely used in advertising, stages, public information displays, sports and transportation facilities and other application fields.
LED display screens are divided into indoor, outdoor and semi-outdoor LED displays according to the use environment. According to the display color, they are divided into single-color screens, two-color screens and full-color screens.
According to the selected devices, they are divided into digital dot matrix screens, direct plug-in LED screens and SMD Screen. What this article is going to describe is the emerging outdoor full-color patch-type SMD display and its dedicated SMD device performance.
Important advantages of outdoor full-color SMD screen display
As we all know, outdoor LED displays all used plug-in oval red, green and blue LED devices a year or two ago. In the past two years, outdoor full-color SMD screen displays with a pixel pitch of 8mm to 16mm are being used gradually emerged and gained widespread application.
In the past, due to the low brightness of SMD, and the waterproof, moisture-proof. And UV-proof functions could not meet the requirements of harsh outdoor environments, outdoor full-color displays were dominated by direct-plug LED devices. Full-color SMD display screens can only be used indoors in large quantities.
With the improvement of LED chip technology and LED packaging technology. The brightness and protection level of SMD can already meet the needs of outdoor use, and the full-color patch-type SMD screen display has more advantages.
That are difficult to achieve with the full-color plug-in LED display. , so it has been used more quickly.
The advantages of outdoor full-color SMD display compared to outdoor direct-plug elliptical LED display are in the following aspects:
(1) Wide viewing angle
The outdoor full-color SMD display not only has a wide viewing angle of 110 degrees in the horizontal direction. But also has a wide viewing angle of 110 degrees in the vertical direction, which is particularly advantageous in some applications.
(2) Good light distribution
The matching consistency of the three brightness’s of red, green and blue oval LEDs at different angles is a very difficult indicator. However, due to the three-in-one design structure of full-color SMD. The three red, green and blue chips are all in in a bracket bowl and cup. The matching consistency of the three brightness’s of red, green and blue at different angles is highly consistent. Thus making the outdoor full-color SMD screen display have very good brightness matching consistency at any angle, reaching Better color real results.
The following 1 and 2 are respectively the outdoor full-color patch type SMD light distribution curve and the outdoor full-color elliptical LED light distribution curve. It can be seen through comparison that the light distribution consistency of SMD has obvious advantages over elliptical LED.
1 Outdoor full-color SMD horizontal direction light distribution curve 2 Outdoor elliptical LED horizontal direction light distribution curve
(3) Light mixing is good
Because the design structure is three-in-one. The three chips are very close together. And the light is mixed in the same bracket cup, instead of three separate oval LEDs. So red, green, and blue light are mixed. The effect is better than the direct plug-in oval LED screen, especially suitable for close viewing.
(4) High contrast
Due to the three-in-one design structure. The full-color SMD is small in size and the LED large-screen information is used to display text, graphics, images, animations, market prices, videos, video signals and other information display screens.
Therefore, the light-emitting area is small and the black area is large, which improves the contrast of the LED display.
(5) Automated production
SMD can be automated using a fully automatic placement machine, with high production efficiency. The circuit design of the full-color SMD display module can realize the two-in-one light board and driver board. Which reduces costs, improves reliability, and improves production efficiency.
Automated patch production can also improve the vertical accuracy of SMD on the circuit board. Overcoming the problem of vertical accuracy of plug-in elliptical LEDs on the circuit board, thereby ensuring better optical effects.
Important parameters of outdoor full-color SMD Screen
(1)Brightness
At present, the brightness of outdoor full-color SMD can meet the brightness needs of outdoor full-color SMD screen display with point spacing of 8mm to 16mm. Among them, the green brightness may reach 1200mcd to 1600mcd, and the whole screen brightness may be higher than 5000nits.
In order to ensure the consistency of brightness across the entire screen. The brightness range of each color should be below 1:1.3, and the uniform brightness ratio of red, green, and blue colors is approximately 3:6:1.
(2) Wavelength
The wavelength range of the three colors of red, green and blue should not be wider than 5nm. Also, the wavelength distribution of each color should be normally distributed.
(3) Attenuation
Outdoor full-color patch-type SMD has a higher application current due to brightness. Since it is used outdoors, in order to achieve minimum attenuation. It has higher requirements for chip size, heat dissipation design, waterproofing, and UV resistance.
At the same time, the brightness attenuation of the three colors of red, green, and blue must be consistent. To ensure that the SMD display screen not only has a smaller brightness drop after working for a long time. But also maintains good brightness and color consistency.
High-quality outdoor full-color patch-type SMDs can generally ensure that the attenuation of red, green, and blue is less than 5% evenly after 3,000 hours of operation, and the attenuation dispersion of red, green, and blue is less than +10%.
(4) Angle
The angle of outdoor full-color SMD generally requires both the horizontal and vertical directions to be greater than 110 degrees.
(5) Waterproof and moisture-proof
The waterproof and moisture-proof performance of outdoor full-color patch-type SMD is a very important key parameter. The use of new PPA materials, silicone materials and the design of new structures can solve waterproof and moisture-proof problems.
If the waterproof and moisture-proof problems are not solved well, problems such as failure, dimming, and rapid decay will occur. The waterproof and dustproof grade of the high-quality outdoor full-color SMD can reach IP67, and the moisture-proof grade is Lever3.
(6) UV protection
Due to outdoor use, the bracket material and potting material of the full-color SMD Screen are required to have the ability to resist ultraviolet rays. SMD that is not UV-resistant will cause yellowing of the PPA and turbidity of the potting material.
Resulting in brightness attenuation and failure. The yellowing rate of outdoor full-color patch-type SMD with good quality should not exceed 5% after 10,000 hours of outdoor work.
(7) Failure force
It is easy to fail under the influence of many factors. LED display information, with the continuous advancement of large-scale integrated circuits and computer technology, LED displays are rising rapidly.
The high-quality outdoor full-color patch-type SMD is effective within 3000 hours. Should be less than 5 parts per 100,000 (50ppm).
(8)Thickness
Taking into account the waterproof factor of the circuit board, the outdoor full-color SMD display needs to be potted with waterproof glue below the thickness of the SMD. Therefore, the full-color SMD display requires a certain height. The current mainstream thickness on the market is 2.5mm.
The development trend of outdoor full-color SMD Screen display
In terms of brightness and cost, LED display price information. LED display integrates microelectronics technology, computer technology, and information processing.
The traditional outdoor full-color plug-in elliptical LED display has irreplaceable advantages in pixel spacing of 20mm and above. With the improvement of Mustang LED chip brightness and LED packaging technology, the price gap between outdoor full-color SMD and elliptical LED has narrowed to 10% to 20%.
Due to the advantages of wide viewing angle, good light distribution, good light mixing, high contrast, and easy automated production. The market share of outdoor full-color SMD Screen displays is expected to grow from less than 10% at the beginning to the same level as the outdoor full-color SMD display. Color plug-in elliptical LED display divides the world equally.
In addition, if you want to read a different article: What are the specifications and models of automotive LED SMD Screen lamp beads?
