Increasing Popularity of LEDs in Signage Applications

Since 2007, LEDs have attained great prominence, and due to high levels of hype the sign trade was quick off the mark to utilise them in every application requiring illumination. Insight held off during the beginning when the new wave of SMD LEDs were being touted as taking over from fluorescent lamps, spots and neon. This was reminiscent of a time several years back when back-lit signs using cases were apparently soon to be eclipsed by ultra slim edge-lit signs. The high cost of edge-lit signs, and their inability to provide sufficient illumination for larger signs were their main drawbacks, which meant back-lit cases retained their popularity.

LED Modules

Come early 2008, Insight felt it was time to look at LEDs in depth, and come up with a suitable system to be sold as our own brand, now named Lumirescent. We started like most companies with the various modules, which were fine for built-up letters (albeit not half as good as neon), but useless for back-lit signs (too dull and spotty).

LED Fluorescent Lamps

We then discovered what the Chinese call LED fluorescent lamps. When we received our first batch it was with great excitement and we had no doubt that fluorescent lamps were finished. However, when we began testing several different brands, and all types (including DIP-style LEDs, SMD LEDs, twin rows, triple rows, plastic casings, ribbed aluminium casings) we soon noticed faults occurring. Some were even live, due to insufficient isolation of the internal driver from the aluminium heat sink. It was not long before our tests revealed the internal driver to be the weak link in the chain. Also, excess heat was prematurely ageing the LEDs.
   So, the hype of 50,000-100,000 hours life for LED fluorescent lamps was just hype after all. In actual fact, some large projects had major failings in just nine months. Insight never sold any, only tested them, but was informed that a large blue chip company in the UK had purchased over a thousand, direct from a company in China with a one year warranty, which is given by most suppliers but not upheld in this instance due to the fact that the tubes were being operated 24 hours per day when the small print recommended 8 hours per day maximum. Even at that, why would anyone bulk purchase these tubes when they are supposed to last ten years but only have a one year warranty?
   If you are considering buying LED fluorescent lamps, just be careful and ask yourself why—if they are as good as the hype would have you believe—Philips, Osram, GE, or any of the large well known companies do not produce them? Also watch out for statistics giving payback time versus fluorescent based on the most uneconomical fluorescent lamps (T12) and stating that fluorescent lamps last only 8,000 hours (you can get fluorescent lamps which last up to 30-40,000 hours now).
   After testing, Insight decided that the only way this type of LED tube could be reliable was for it to have an external driver. This would of course make them less attractive and more difficult to use. Many of the LED fluorescent lamp manufacturers are now mounting the driver remotely, or on the end of the tube so that it can be changed when it burns out (long before the LEDs). Also, life statements are now dropping to around 35,000 hours (less than some fluorescent lamps). If you use them, ask for proof of the claims they make. If they cannot provide it, how do they know the claims are true?

Rigid LED Strips

Insight then moved on to testing rigid aluminium strips with SMD LEDs. This was a good product, but as it was available only in 500 mm or 1,000 mm fixed lengths only: too limiting.

Flexible LED Strips

It was then decided to develop a similar product which could be cut to any length. Lumirescent Flexible Strip had arrived.
   Launched to the sign trade in November 2008 after almost 9 months of continuous tests, both by us, and our manufacturers, we began with just one type of strip, now named Lumirescent Medium. Although at that time comparable in brightness to the market-leading systems, it was still far short of brightness when compared to fluorescent, so we designed and produced two other versions, namely Bright and Superbright. Results of our tests comparing Lumirescent strip with competitors can be found on our web site here: LED Comparison.