The conditions of the cabinet 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 Chavez*
The goodness of a video wall is in the sum of its parts. A single component malfunction will affect the final display. Hence the importance of identifying potential hotspots in advance. With the emergence of new standards and the abundance of alternatives to choose from, it is crucial to ask the right questions before deciding on the best solution for our project. These are the main questions before buying an LED display.
Do all the 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 while the uniqueness of each pixel prevents total homogenization, selecting them within a more uniform range of brightness and color allows the manufacturer to get a more harmonious image across the screen and maximize power efficiency.
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 sharp and vibrant image the figure must 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 place along an LED display. To achieve the deepest levels of black and the highest possible contrast, these packages must be constructed with a dark encapsulation material, usually made of epoxy resin. Be sure to order black SMD LEDs.
Who manufactures your driver and integrated switching (IC) circuits?
ICs are a fundamental element for the performance of your display. Without a driver and quality switching ICs, there is a risk that the pixels on the display are not sufficiently controlled, which will adversely 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 "ghost effect", the appearance of dull stripes or color changes.
How to keep the display cool?
The cabinets that house the LED modules allow the heat to leave the display thus cooling it passively (instead of using an active fan). This configuration also allows to reduce, both the overall size of the display – which expands the possibilities of design and installation – and the noise emission, something fundamental for many applications, especially when the viewing distance is short.
The conditions of the cabinet 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 goals in mind when asking about the LED cabinet and find out if your display plans are feasible.
Where are the access points for maintenance?
The best designs facilitate full front access, thus allowing to replace mosaics and repair the electronic elements without the need 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 remove the entire cabinet, minimizing maintenance time and operating costs.
Can we see the product in action?
Attending fairs or requesting live demonstrations from various vendors will help you in your goal of achieving the best visual quality. Remember that many marketers will offer you their own content to maximize impact and minimize deficiencies. When comparing different sellers try to use a coherent visual image package (preferably video). Make sure you choose content representative of your specific app.
When viewing the images:
› see if the image is uniform across all modules
› look for "ghosting", image breakage or other anomalies
› use a light meter to check brightness
Is the display certified at the system level?
When LED components are used simultaneously, their interactions can lead to problems, such as the appearance of levels of electromagnetic emissions higher than current standards. Obtaining a certificate at the system level confirms that it is secure in its entirety and that you can rest assured. If an LED product is purchased and installed without a system-level certificate, this 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. A proper mix of technologies and services will help create a complete experience to the satisfaction of your audience. Make sure your manufacturer warrants the product and installs it properly if problems arise.
*Juan Carlos Chávez, is director of Christie in Latin America.
