LED Displays, Unmasked
We are all familiar with the caveat “what you see is what you get,” and the ancillary “seeing is believing.” For years in AV, we applied this general rule to the overall display industry. We looked at an image and judged the color, contrast, and resolution … but then we would turn our attention to the hardware and components of the display devices that produced the images. Back in the day when we only had projectors to work with, there were legitimate and discernable differences between LCD, LCoS and DMD digital technologies from various manufacturers and between models, and of course, the resulting images they produced. In the good old days of the InfoComm Projector Shootout, we could see projectors side by side, evaluate the images, and then delve into the display hardware as a necessary part of the evaluation process. I add parenthetically that back in the day with projectors we actually did board level repair and in many cases component replacements as well. Soldering irons were your best friend… but I digress.
Fast forward and we no longer have formalized and vendor neutral side by side comparisons of the major display vendor’s products. With the maturity and reliability of most displays (both projectors and LCD flat panels) there is an understandably declining awareness and involvement in the construction and individual components of the “machines” that produce the images. The primary focus is on the output images themselves. After all the image is what matters most… right? The correct response is “yes”, of course, but also increasingly “no” when it comes to one burgeoning display technology. Of course, I am speaking about direct view LED displays. Suffice it to say that this category (which is far better than in years past) is truly not yet mature (in the sense of all display technologies) and it is time to unmask direct view LED displays and examine what is beneath the surface of the pretty pictures you see. As you will see (or not, until it may be too late to do anything about it), the devil or angel is in the details!
Looking at conventional LCD flat panels we can see they are mature in their manufacturing processes, and today only truly receive incremental improvements as time goes on. There is a commonality of the manufacturing process among vendors, and with many years of reliable operation under their belts there is little need for integrators to delve deeply into their component parts that have “stood the test of time”. If an LCD flat panel fails in the field, it normally boils down to a complete product replacement, or at most a board level service on a limited number of components such as a power supply and input card. This is typically covered under the manufacturer’s standard on-site parts and labor warranties. Today if the necessary inputs are on the display and notwithstanding the need for display calibration (i.e., video walls and postproduction), it is about as near to plug and play as you can get. Suffice it to say most LCD displays today are (relatively) bullet proof and the images produced out of the box look spectacular. As good as this sounds (and it is with LCD flat panels), with direct view LED there is more than a pretty picture on screen for designers and integrators to consider.
The fact is that many of us have become lulled into a justifiable sense of security with these mature displays. Pick a brand that you like and the specs you require, protected by multi-year on-site warranties and rest assured there is little more that you need to consider. In fact, what you see is typically what you get and your experience with these products over the last decade has proven your trust is well founded. Perhaps stating the obvious (to some), but direct view LED is different than traditional LCD flat panels both in their technical and design evaluation, and the way you need to purchase. Direct view LED displays are not built the same way, and they are not mature from a technology and manufacturing point of view in the same sense that LCD flat panels are. What you see is not necessarily what you get. Please permit me to explain so you are forewarned and forearmed to make the best direct view LED decisions for your projects.
Direct view LED displays are nearly unlimited by size and format. They are seamless, the colors are vibrant, contrast deep, and the brightness unparalleled. The confusion with direct view LED is that while they look spectacular, they tend to look alike. You go to the big trade shows like InfoComm where there are 50 to 70 direct view LED vendors on exhibit, and most of them look great. In several independent comparisons over the last couple of years we have seen a commonality of superb images from major manufacturers and even some of the lesser-known brands. In short, a great performing 1.5mm dot pitch display tends to look like another of the same specification. While this is excellent at first glance (pun intended), the difficulty lies beneath the surface, much like the iceberg where 2/3rds (and the danger) lies beneath the surface. A superb image is the price of entry into the market, but the differentiation between vendors lies beneath. We hope to provide insights that will help you decide why to buy from one company versus another given most have superb images.
Let’s begin with confusion… and the fact that there are well over 100 companies (mainly out of China) that claim to be manufacturers of direct view LED displays. A few you will most likely be familiar with (around 20), but the majority are names you would not recognize. Research shows that some are in fact manufacturers at varying levels and yet others are simply assemblers. More on that later. Also, unlike LCD where the manufacturing process is mature and relatively common among vendors, with direct view LED there is great variation in components and how they are assembled. Also keep in mind that processors, drivers etc. tend to be the same across the board of manufacturers so differentiation (from poor to good and in between) boils down to design, construction, quality control, final testing, and more.
Each of the following topics should be taken into consideration as you determine who to work with:
- OEM and ODM manufacturing
- OEM stands for Original Equipment Manufacturer. They manufacture products based on designs provided by customers. The customer is responsible for the branding and some design aspects, while the manufacturer owns rights to other design aspects.
- ODM stands for Original Design Manufacturer. They design and manufacture products for customers, and then the customers brand and market the products as their own. This is also known as private label manufacturing.
- Key takeaway
- In the direct view LED display world, it is difficult to know who does what. Some companies build most of their own products under their brand and others buy from OEM or ODM manufacturers and then market under their own name. OEM and ODM are a fact of life and not necessarily a negative but the quality of what they produce needs to stand up to the same quality level as if the product came out of the brand in a vertically integrated company.
- Vertically integrated manufacturing versus parts assemblers
- Vertically integrated manufacturing refers to a company owning and controlling most or all the product supply chain. It involves integrating various stages of production, from the procurement of raw materials to the manufacturing of components and final assembly to the distribution of the finished product.
- A parts assembler procures component parts from a variety of suppliers and makes a finished product from the sum of those parts. Other than the final assembly they have little control.
- Key takeaway
- No one in the direct view LED display world has a 100% vertically integrated capability. No matter the source, the critical issue is to be in control of the design, engineering, manufacturing, QC and testing of finished delivered goods.
- Type and grade of LED
- There are 6 companies that manufacture the core diode and clusters for LED displays. They are Cree, Nichia, Nationstar, and Kinglight, with two lesser-known companies on the lower end of the spectrum. In each case there are ranges or levels of LED priced in accordance with their construction and performance.
- Key takeaway
- One of the driving factors of cost for a direct view LED display is the diode or clusters of LEDs. There may be as much as a 5x or more cost differential among the various levels of LEDs from a manufacturer. The tradeoff is performance and lifespan.
- Quality management, control, and testing
- ISO 9001 is a set of international standards on quality management (QM) and quality assurance. It requires organizations to establish, implement, and maintain a complete quality management system to ensure that the quality of products or services meets the requirements of customers.
- Quality control, or QC, is the process to ensure that a product or service adheres to a predefined set of quality standards or meets the requirements of customers or clients. Done properly this involves extensive training, creating benchmarks for measuring product or service quality and testing to check for any significant variations in quality.
- Key takeaway
- In both QM and QC, the company sets up their own processes and rules and then ISO 9001 audits to ensure that the rules the manufacturer has set up are in place, followed, and documented. The depth of QM and QC adherence ultimately determines the quality of the delivered product.
- MTBF
- Mean time between failure (MTBF) is a measure of the reliability of a system or component. It’s a crucial element of maintenance management, representing the average time that a system or component will operate before it fails. MTBF is calculated by dividing the total time of operation by the number of failures that occur during that time. The result is an average value that can be used to estimate the expected service life of the system or component.
- Key takeaway
- MTBF is not a published specification but rather part of the engineering, manufacturing, QC, and testing process. The MTBF value is a measure of reliability, but it is not a guarantee of reliability. It measures how frequently failures are expected to occur but doesn’t necessarily take into account every external factor.
- Certifications (required in the USA)
- FCC and EMC
- Federal Communications Commission (FCC) certification is for electronic and radio equipment sold, distributed, or used in the United States. FCC certification requires products to meet specific technical standards to ensure that they meet FCC requirements in terms of electromagnetic compatibility (EMC) and radio frequency radiation (RF). This is one of the necessary conditions for entering the U.S. market.
- Electromagnetic compatibility (EMC) certification is the process of testing a device to ensure it can operate safely and effectively in an environment with other electronic devices. EMC certification verifies that a device’s electromagnetic emissions meet standards and that it can withstand normal levels of emissions from other devices
- UL (required in many cities and counties)
- LED display UL certification, in short, means that LED display products have passed a comprehensive safety inspection and evaluation conducted by an authoritative third-party organization, Underwriters Laboratories (UL). LED display UL certification, in short, means that LED display products have passed a comprehensive safety inspection and evaluation conducted by an authoritative third-party organization, Underwriters Laboratories (UL).
- ETL certification, or the ETL Listed Mark, is a product safety certification that indicates a product has been tested and meets North American safety standards. It’s proof that a product complies with safety standards and is accepted by authorities and code officials in the US and Canada.
- Key takeaway
- To sell electronic products in the USA FCC certification is a requirement. The caveat with FCC certification is the preponderance of fake certifications by some unscrupulous vendors. If discovered the penalties are severe. Both UL and ETL are Nationally Recognized Testing Laboratories (NRTLs) that are approved by the Occupational Safety and Health Administration (OSHA) to test products for safety. UL is a requirement in most populated regions in the USA. In some areas ETL is seen “as equal”.
- FCC and EMC
- As-built testing and calibration before delivery
- This should be the last step in manufacturing and QC before delivery. This includes all the parts set up as a system along with basic display calibration to a set output standard.
- Key takeaway
- The process should be outlined in detail and any faults discovered, corrected and reported per ISO9001.
- Warranty and support
- Unlike the warranties on LCD flat panels that are parts and labor on site, direct view LED warranties typically cover parts only with on-site support the responsibility of the integrator. The defective parts are returned to the manufacturer and repaired parts are sent back.
- Key takeaway
- This is a huge issue relating to many of the topics listed above. This is why spare parts are critical when installing a direct view LED. It is a matter of reliability of the display components (think QC and MTBF), time to troubleshoot and send back spare parts and then time for their return and being reinstalled. Claiming support before the sale and actually providing support /or two different things.
To be clear there are some excellent providers of direct view LED, and their quality and support is beyond reproach. The problem is separating the proverbial wheat from the chaff. With over 100 vendors vying for your business, it is tough to know who to listen to and which one is the best fit. One size and one company does not fit all especially in direct view LED. Prices and quotes are all over the place. I advise people to conduct their due diligence up front including the topics noted in this article. You may not find definitive answers in each area but if a vendor ignores these topics or wants to change the subject go to the next one on your list. Once the upfront work is done (ignorance is no excuse) I tell those who ask you not to spend more than they should but not less than they need to. One last trite but true admonition, “you get what you pay for.”