Monday, 15 Jun 2015 08:34 GMT

LED Modules

While the end built-up sign system often takes centre stage, Jo Golding investigates how development of the humble LED module is revolutionising the market over traditional lighting

A very bright idea

The LED sector has seen significant growth in recent years. Although it is normally the colourful sign designs and colours that catch the eye, it is the ‘behind the scenes’ LED module that is the real shining light behind this type of signage.

The LED module consists of one or more single LEDs mounted onto a board, which can be used on its own or to plug into another unit. Proper installation is important and installers often use self-adhesive tape or self-tapping screws to bond the modules. It is also crucial to protect the module from outside factors.

“A good LED module should have an IP67 fully waterproof rating and feature high quality high lumen output LEDs. It also needs to prevent damage to the LEDs from heat and moisture. The IP67 rating seals the LED, preventing moisture damage,” says Phil Shadbolt, chairman and chief executive officer of Zeta Specialist Lighting.


Zeta Specialist Lighting have moved away from string LED modules in favour of more robust large-scale technology



Shadbolt refers to the Zeta Embedded LED Panel (ELP) as a product that effectively deals with heat. He says: “One major advantage of Zeta’s ELP is that it has a large aluminium panel that acts as a ‘heat sink’. There have been many instances where people have selected an LED module that has not benefitted from research and development investment in ‘heat sink’ technology and this has caused the LEDs to fail.”

The modules are getting more efficient, more varied in terms of what’s available, and better priced as the years go on ”


Graeme Hoole, production manager of The Sign Group (of which We Love LEDs is a subsidiary), says: “The modules are getting more efficient, more varied in terms of what’s available, and better priced as the years go on. It’s only been the last few years where they’ve been able to compete with tubes. Once tubes are a bit more obsolete, I think you’ll see an even bigger variation on what LED modules are available.”

Number one

Michelle Kelly of Vink Lighting Solutions provides an in-depth analysis of how LED modules has developed, saying: “In the space of a few years, LED systems for signage applications have improved to such an extent, that they have become the first choice method of lighting for both built-up letters and back-lit light boxes. However, these improvements have, in themselves, created issues for manufacturers, specifiers and sign makers as to how they can be best applied.”

Kelly refers to the E.C.A. scheme, which was implemented by The Carbon Trust, which has inspired leading manufacturers to continuously improve LED light output while reducing energy consumption. This initiative has been so successful that luminous efficacies in excess of 100 lumens per watt are now considered the norm, while still managing to maintain lumen depreciation figures of less than 30 percent after 50,000 hours of use.


Vink Lighting Solutions is a key supplier of GE Lighting LED modules, seen here in use by Mercedes for one of its flagship showrooms



The E.C.A. scheme parameters relating to colour rendering, luminous efficacy, and lumen depreciation on white light emitting diodes published in 2012 proved to be far less stringent than the improvements the major manufacturers have since developed. This has led to the effective ‘closing down’ of the scheme now that the industry has ready access to highly efficient systems from a number of manufacturers.

According to Kelly, sign designers and specifiers are requesting shallower and shallower return depths for both letters and light boxes. LEDs being single point light sources are finding it increasingly difficult to perform well at these shallower depths while providing perfectly even face illumination.

O Factoid: The heat produced through light affects the longevity of not just the individual LED but also the entire LED module which is why it is important to divert the heat away through proper installation. O


Kelly continues: “A typical exposed SMD (Surface Mounted Device) emits light with a beam angle of approximately 120 degrees which, unless the diodes are very closely packed together or the distance from diode to sign face is very large, will show on the sign face as a number of bright spots. This problem will only be accentuated if the individual diode brightness is increased. The more diodes required to evenly illuminate a sign, the greater the solution cost, the more energy consumed and the less chance the sign will be granted advertising consent.
 
“Without a protective cover, the diode is prone to physical damage, moisture ingress, corrosion and pollution damage. These factors can result in rapid lumen depreciation caused by moisture ingress, colour shift where pollutants degrade diode phosphors effectively turning White LEDs Blue, Yellow or Pink, and in the case of physical damage, catastrophic failure.”

Manufacturers’ LED performance now cannot continue to improve. On the contrary, more end clients are asking for LED systems to have a dimmable option in order to conform to standards required for local authority advertising consent. (A typical urban authority would not knowingly app-rove a face-lit sign with a luminance of greater than 1000 candelas per sq/m).


Zeta Specialist Lighting’s solar signage kit was used by the IS Group at the Pier Head on the Liverpool Waterfront, creating a nine metre high totem



Kelly continues: “Once again, the major manufacturers have led the way in developing innovative solutions to address many of these issues. Clearly, the quest for more light is now over, and the new ‘Holy Grail’ is to use all that extra light in the most efficient manner possible—Optical Lens Technology has proved to be that Holy Grail.

“Optical Lens Technology in modular LED systems has gone through an evolutionary process beginning with a simple clear cover over the diode, the sole function of which was to provide physical protection, to an array of optics on the same module manipulating the light to suit a particular application.”

Many of the major manufacturers have developed specialised optics such as GE Lighting’s ‘Optilens’ system, Osram’s ‘Flat Ray Technology’ or Agilight’s ‘Versalenz’ Advanced Op-tics System.

All the systems work on the same principle where the optic spreads the light beam from the diode allowing for wider module spacings and shallower return depths. The principle is generally known as the ‘Batwing Beam Pattern’, but has many variants as shown in the following ray plots published by Agilight.

The plots above represent the pattern of light manipulated by the lens, and will create completely different effects in terms of light intensity on the sign face at different return distances.

Intelligent use of these modules with their specialised optical lenses depending upon a particular application will result in using far less LEDs, significantly reducing cost and energy consumption whilst still providing bright, evenly illuminated signs.

Kelly concludes: “Another clever innovation is the Tetra MiniMAX MS LED system from GE Lighting. The light pattern pictures on the left compare the difference between the MiniMAX MS optic and a standard light pattern with a typical batwing optic whereby the light is stretched to best suit very narrow stroke width, shallow return letters. Combined with a very small module size, (35 x 10 x 9mm) and a module brightness of 36 lumens, the module will provide even illumination at return depths as low as 38mm even when spaced widely apart.

“Clearly, this type of optic would not suit every application, but is a good indicator that the idea of a ‘one module fits all’ approach to sign design is a thing of the past, and individual module cost is not the critical factor when producing an economical sign.”

Taking over

Some say the LED market has now completely dominated all traditional lighting forms, including neon and florescent tubes. A point that Shadbolt agrees with: “Yes absolutely, I firmly believe we’ve reached the tipping point. LEDs are flexible, they produce uniform lighting, are longer lasting, energy saving and eco-friendly. The financial constraints have also long gone—the cost of LEDs has come down considerably and the payback period is often shorter than people think.”

He continues: “In today’s climate, the opportunity to lower your business’ energy bills and reduce its carbon emissions is a compelling proposition. LEDs use significantly less power than traditional lighting solutions and last much longer, Zeta’s Embedded LED Panels last for 40,000 hours (average rated life)—almost three times longer than a traditional fluorescent.

“In addition, the smaller monoliths incorporated PIR sensors so that they only light up when visitors approach. The bill to lay the cabling required for traditional lighting would have run into a six figure sum.”

Robert Coulson, general manager of LED Solutions, agrees that LED has dominated traditional lighting for many years as the cost has made it easier to do so: “It was always going that way. You could always say the brightness is better, the efficiency is better, the lifetime is better, but now we are truly at a point where the price is getting almost the same.

There’s only a few applications now where it’s more worthwhile using fluorescents than it is using LEDs”


He adds: “There’s only a few applications now where it’s more worthwhile using fluorescents than it is using LEDs. Our parent company, they’re pretty much fully LED now. We don’t get many enquiries for it either, and neon’s been gone for years.”

John Wiggins, national accounts signage for Oshino Lamps, says: “LED has taken over the signage market. The trick for the sign-maker is to find a reputable company that’s accredited through various agencies so the product they’ll get is good value for money. Quality at the right price is always the right answer.”

LED has taken over the signage market. The trick for the sign-maker is to find a reputable company that’s accredited through various agencies so the product they’ll get is good value for money ”


He adds: “There’s no question about it. It is impossible to use historic filament lamps or fluorescent tubes in signage now, it’s just not worth doing. The biggest problem by far is the maintenance. If you’ve got a sign on the side of a building that’s 10m up, the last thing you want to do is go back up and change a lamp.”

Hoole believes LEDs are the route people go down for illumination, but many are reverting back to tradition: “Some people are starting to incorporate an old fashioned style. With fluorescent tubes, they’ve pretty much seen their day in signage now. Price wise LEDs now are just winning in nearly every aspect.”

Hoole also believes it is too soon to rule out neon. He adds: “For now, until neon is banned, neon is still a big player in signage. Even though it is retro looking, it’s cutting edge because it’s never been done before.”

Slimming down

In terms of trends, Zeta Specialist Lighting believes things have moved away from LED ‘string modules’ towards large area ‘LED solutions such as the Zeta Embedded LED Panel (ELP) or Bespoke LED Lattice Ladder’.

“Ideal for use in advertising light box backlighting and signage, the Zeta Embedded LED Panel is a highly efficient LED panel that combines excellent energy saving properties with superior lighting levels. The Zeta Bespoke LED Lattice Ladder, provides sign makers with a great way to illuminate larger advertising poster cases or retail facia lighting,” says Shadbolt.


Phil Shadbolt, chairman and chief executive officer of Zeta Specialist Lighting, says ‘LEDs are flexible, long lasting, energy saving and eco-friendly’



He adds: “Large area LED solutions deliver a much better distribution of light and are much easier to work with. They are also much easier to fit than an LED ‘string module’ product. Zeta’s ELP for example is ultra-slim—just 3.5mm deep, waterproof and most importantly, it’s available in bespoke sizes.”

Coulson believes there is no requirement for one type of LED over another anymore, saying: “Every module from every supplier is kind of the same in just a slightly different aesthetic. It’s all wide angle lens modules now, almost fully.”


We Love LEDs rigorously tests its modules, and is so confident that they are used in all the products created by parent company The Sign Group



Coulson believes one trend, that has also gathered speed in the smart phone and television market, is emerging strongly. He adds: “The only thing I’ll say is over the last few years, every-thing’s going slimmer. There are lots of modules that advertise they can do down to 30ml but it’s still difficult. The rest of us struggle to get down to a good level of even illumination below 40ml.”

Agreeing with this analysis of market trends, Wiggins says: “The market for modules gets polarised. Everybody wants to have the thinnest possible sign with the brightest output or they want the fewest number of modules in the biggest sign they can. We try to cater for either end of the market and not just sit in the middle.”

New advances

One company following the trend of slimmer modules is London based trade supplier, UK LED Signs. Their range of mini modules, which have a dimension of 29 x 6 x 6mm, provide a compact solution ideal for low and narrow channel letters.

Their Samsung LED modules range from three bulb circular modules to two bulb RGB modules.

“All of our parts suppliers are Korean. At the beginning we used Chinese LEDs but after nine months, the lighting became weaker and weaker. So we switched to Samsung to get a better quality and nobody has complained at all so far,” says Isam Kalel, manager of UK LED Signs.

Zeta is also a strong advocate of quality over quantity when it comes to LED technology. Its solar signage kit is a case in point. It is a bespoke solution for lighting outdoor totems and monoliths and was used recently by the IS Group at the Pier Head on the Liverpool Waterfront.

“Three, nine metre high totem signs and ten double-sided and one four-sided directional monoliths were illuminated thanks to Zeta’s innovative LED solar powered lighting,” explains Shadbolt.

LED Solutions’ meanwhile modules are mostly used for letters and light boxes, with very little to no digital trade. Coulson says: “We do the quoting, the layout, wiring layouts, recommendations etc. for the companies to use. We do offer, for big projects, that companies come to us for site visits, especially for RGB work. With around five people on the LED side of the company, they all get involved.”


The Sign Group, and their sub-company We Love LEDs, can create light boxes using substrates such as stainless steel, aluminium, and composite. Pictured: One of its more quirky product demonstrations ‘Chicken in a Box’ showcases the flexibility of its technology



Daehan are LED Solutions’ historic module, which they have been supplying for years. Though in recent times, they have been moving away from them in favour of better technology.

“Going a little away just purely because the technology we’re getting from the new companies is better. They’re a little bit behind and a little bit expensive for old technology,” says Coulson.

They have also just become the UK distributors of Italian LED manufacturer, Hitechled. Coulson explains how the modules have been doing well as they provide a ‘very high efficacy’ but at a low cost.

This pursuit of quality is also one pursued by Oshino Lamps, but Wiggins explains that getting the application right is also key : “We have probably one module that’s one of the most efficient on the market with a reasonable average brightness and another module which is probably one of the highest efficiency modules on the market with the highest output. One is for small boxes, one is for large boxes.”

Wiggins has also noticed concerns amongst retailers. He explains: “What we’ve found recently is that the major retailers are getting more discerning about the wavelength of the white colour that they want. So they want standard white letters but ones that compliment what they do.


The LB200 module from We Love LEDs can be used for large flex face light boxes and is very bright



“For example, we do quite a bit of work for people who work for Dior and Chanel, and those two companies have a propensity for 4,000 and 5,000 kelvin white colour temperature LEDs, which we sell quite a lot of for that market.”

In terms of balancing power and light, Wiggins believes sign-makers have to understand you cannot have it both ways: “If you sacrifice power, you will also sacrifice light. If you increase the power, you increase the light output, and it has nothing to do with the efficiency. So you can have a module that’s got very low power, very low output, but actually if you divide the wattage into the output you’ll find it’s very efficient.”

At We Love LEDs, their new modules are drawing in sign-makers for this very reason, as Hoole explains: “The new modules that we’ve got are the EL200 and LB200, these are very bright modules. The LB200’s are for use in large flex face light boxes, they’ve got a very wide angle which means you don’t need to put as many in and they’re incredibly bright.

“The EL200’s are for flex face or standard light boxes but instead of them getting put directly to the back facing forwards, they get put on the inside returns pointing up and down. They’ve got a very focused beam of light which means it travels further through the box, which gives you an even illumination.”

Hoole concludes: “People aren’t just taking the bulbs themselves but they’re actually taking control gear, so they’re taking programmable controllers so the bulbs can be individually controlled to create some really interesting patterns. It lifts that sign which would have been a normal trough letter to the next level.”

After talking to the core manufacturers of LED modules, it is clear that developments in the sector are significant with more colours, types, and variations being created all the time, adding to the gradual dominance of LED in the market. Whether traditional lighting forms will be able to innovate, survive, and find their own niche is unknown, for now.


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