The cabinet conditions are fundamental for the use of the LED display. The absence of adequate cooling or easy access could limit the operation of the installation.
Juan Carlos Chávez *
The goodness of a videowall is in the sum of its parts. The malfunction of a single component will affect the final display. Hence the importance of identifying in advance the possible critical points. With the emergence of new standards and the abundance of alternatives to choose from, it is crucial to ask the right questions before deciding the best solution for our project. These are the main questions before purchasing an LED display.
Do all pixels come out of the same bin?
The process of creating pixels is very complex, and it is impossible to get two identical pixels. The best manufacturers select them based on brightness and color, a process known as binning.
The use of pixels within a controlled bin range guarantees a quality display. And although the unique character of each pixel prevents total homogenization, selecting them within a more uniform range of brightness and color allows the manufacturer to obtain a more harmonious image across the entire screen and maximize the efficiency of the power.
What is the fill factor of your screens?
The fill factor is the proportion of the screen covered by light-emitting pixels. It is impossible to reach a fill factor of 100%, but if you want to achieve a clear and vibrant image, the figure should be high (minimum of 40%).
Do you use LED packages with surface mount device (SMD)?
The SMD package has the mission of keeping each pixel in its place along an LED display. To achieve the deepest levels of black and the highest possible contrast, you have to build those packages with a dark encapsulation material, usually made of epoxy resin. Be sure to request black SMD LED.
Who manufactures its driver and its integrated switching circuits (IC)?
ICs are a fundamental element for the performance of your display. Without a driver and a quality switching IC there is a risk that the display pixels are not sufficiently controlled, which will negatively affect the uniformity of brightness and color. If the CIs are of low quality, the passage of time will cause defects to emerge, such as the so-called "phantom effect", the appearance of dull fringes or changes in color.
How to keep the display cold?
The cabinets that house the LED modules allow heat to escape from the display, thus cooling it passively (instead of using an active fan). This configuration also reduces the overall size of the display -with which the design and installation possibilities are extended- as well as the emission of noise, which is fundamental for many applications, especially when the viewing distance is short.
The cabinet conditions are fundamental for the use of the LED display. The absence of adequate cooling or easy access could limit the operation of the installation. Keep your objectives in mind when asking about the LED cabinet and find out if your display plans are feasible.
Where are access points for maintenance?
The best designs facilitate full frontal access, allowing to replace mosaics and repair electronic elements without having to disassemble the installation. Most products also require rear access for some parts. It is convenient to know in advance which components we have access to and from which side of the mosaic. The best products are those that allow the individual replacement of the mosaics by the front of the LED videowall without having to extract the entire cabinet, minimizing maintenance time and operating costs.
Can we see the product in action?
Attending fairs or requesting live demonstrations from several vendors will help you in your goal of achieving the best visual quality. Remember that many sellers will offer their own content to maximize the impact and minimize deficiencies. When comparing different vendors try using a coherent visual image package (preferably video). Make sure you choose content representative of your specific application.
When viewing the images:
> See if the image is uniform throughout all the modules
> Look for "ghost" effect, image breakage or other anomalies
> Use a light meter to check the brightness
Is the display certified at the system level?
When LED components are used simultaneously, their interactions can give rise to problems, such as the appearance of electromagnetic emission levels higher than what is established by current standards. Obtaining a certificate at system level confirms that it is safe in its entirety and that you can rest assured. If an LED product is purchased and installed without a system-level certificate, it may be required when the installation is carried out. It is advisable to ask each of the potential vendors if certifications are required and if these will increase installation costs or cause delays in the project.
Can you offer a complete solution? Do you offer extra services and products?
The best suppliers work side by side with the client to create a solution that makes their project a reality. Ask if they offer additional products, such as processing management, content and structures. An adequate mix of technologies and services will help create a complete experience for the satisfaction of your audience. Make sure your manufacturer guarantees the product and installs it properly if problems arise.
* Juan Carlos Chávez, is director of Christie in Latin America.