Solid state lighting technology is becoming an increasingly popular way of illuminating the home theatre screen. With no need to replace lamps, limited user maintenance and low total cost of ownership, it’s easy to see why, writes Callum Fitzpatrick.

Replacing projector lamps has been a pet hate for end users for a long time – it can be tricky, it’s expensive and it can require further calibration of their system.

It’s no wonder then that many home theatre enthusiasts and commercial enterprises are looking to solid-state light sources in their projectors.

For a while, a common complaint of solid-state technology was that its luminosity simply didn’t live up to that of ultra-high-performance (UHP) lamps. However, lampless solutions are now beginning to catch up, with up to 4,000lm being touted by several manufacturers.

Of the two current solid state light sources – lasers and direct output LEDs – laser is the brighter of the two, while LED arrays are much cheaper to manufacture. That’s why a hybrid is a popular alternative – this blends the economy of LED with the brightness of laser.

Casio first pioneered the concept of hybrids and it has dominated the education market with its range of short-throw data projectors. A very similar technology is now implemented by Viewsonic in its home theatre range. Both Casio and Viewsonic’s chromacity reading shows an impressively wide colour gamut, with the Viewsonic Pro 9000 offering 100,000:1 contrast ratio from a DLP Darkchip3 DMD and native HD 1080p (1920×1080) resolution.

This is all achieved through a single DLP chip. Red colouration is produced by LED arrays, while green is created by a blue laser fired at a rotating phosphor wheel. These colours are then directed onto the DLP chip. It is imperative that the wheel rotates as this spreads the intense energy from the blue laser. However, a worry is that introducing a moving part onto an otherwise solid-state light source could introduce a mechanical point of failure.

Just Lamps, distributor of projector lamps, has introduced a sister company that specialises in distributing projectors with a solid-state light source, the aptly named: Just Lampless.

The company’s group finance director Marc Murray says that consumers and home theatre enthusiasts are beginning to realise that when it comes to projectors, luminosity isn’t everything.

“If you’re planning to watch movies in a bright room, in Queensland, in the middle of summer, it doesn’t matter how many lumens your projector boasts, it isn’t going to work properly. No projector is going to overcome that amount of ambient light, so anything over 2,000lm is wasted.

“It seems that we’ve basically had a lumen war in the industry over the last 10 years simply because we can.”

Further, the more lumens your projector outputs, the more wattage will be required to power the bulb.

“You end up having to dissipate a significant amount of heat,” Marc adds.

“There are a lot of home owners that got talked into buying a big, bulky projector and later found they had to cool the room in the middle of winter just to get rid of the heat.”

Due to the efficiency of solid-state lighting technology, laser and LED sources emit almost no heat.

“A UHP burns at around 2,000°C, so a significant amount of electricity is required to maintain that. It is effectively why a bulb burns out – over time, the sheer heat of the spark melts the anode and diode. As the lamp gets older, you have to input additional electricity to create the spark. If it wasn’t for the fail-safes built into projectors, you would eventually melt the whole unit,” Marc says.

The majority of lampless projectors are rated for 20,000 hours – as with UHP lamps, after this period, the manufacturer estimates the brightness will have degraded 50% of what it was at the time of purchase. This is significantly higher than the common 2,000 hour rating of a projector lamp. The problem is that the customer inevitably has to pay for this privilege.

Marc says that many commercial customers will justify the initial expenditure by calculating the total cost of ownership, whereas home users solely focus on immediate price.

“Commercial customers will do the sums – they calculate an asset’s cost over a period of time and find out how much it will cost their business. They realise that if they have to replace the lamp twice over a five year period, it is already worth paying extra for a lampless projector. Home owners are more likely to choose the cheapest initial investment and worry about further costs when it comes out of a different paycheck,” Marc says.

What’s more, for businesses requiring several projectors, such as an education facility, the savings are further compounded.

“If you’re in a lecture theatre with a projector on the ceiling 10m in the air, you have to shut down the room, hire a cherry picker and pay a licensed worker just to get the thing down. If you have to do that in 10 rooms, it becomes a costly enterprise. And that’s before you calculate the additional energy costs of running a UHP unit,” Marc adds.

As well as the established monetary savings, lampless projectors propose a much more environmentally-conscious proposition. Not only can it be an inconvenience to dispose of mercury-based lamps responsibility, but the reality is, we may eventually arrive at a point where traditional UHP projectors are banned completely.

“If you want to pay to have your lamp recycled, you have to pay the shipping costs at the very least. That’s why most householders will simply bury it in their bin. However, an institution isn’t going to take that risk – a worker won’t jeopardise their job just to save their employer $20.”

Just Lamps offers a lamp disposal service, but Marc says very few enquiries are received. Given that the company sells around 15,000 lamps a year, it’s likely that a significant amount of mercury is currently floating around Australian landfill sites.

In Australia, Lamp Recyclers also offers an efficient solution for collection and recycling of mercury-containing waste lamps. It is a signatory to the federal government’s FluoroCycle Scheme.

The laws on mercury wastage are much more stringent in Europe, with the Waste Electrical and Electronic Equipment (WEEE) Directive taking a firm stand on the issue.

“In Europe you will be prosecuted if you’re caught throwing UHP lamps in the bin. The WEEE Directive is even looking at making projectors using UHP lamps illegal,” Marc says.

“They would have to allow for a six year transition period, but if it does go ahead, Australia will surely follow. The fact is, if the law is passed in Europe and America, there will be very few companies making these projectors anymore.”

As with any technology in its early adoption phase, the major drawback for lampless projectors is currently its high price.

However, this is truer of laser projectors as LED arrays are comparatively inexpensive – the major cost comes from the DLP chip, optics and power converter. That’s why LED technology is beginning to flourish at the lower end of the projector market.

“Small, portable LED-based projectors are incredibly popular with gamers and general consumers, but they’re also a major hit with people on the road, such as grey nomads and miners,” Marc explains.

“They are able to carry a projector around in their back pocket that gives them a 50” screen in seconds. It’s completely portable and unlike a TV or a massive projector, nobody can steal it while they’re away from home,” Marc says. 

“It may not have the same output as a dedicated home theatre projector, but it opens up a wealth of possibilities. You can lie on your bed browsing Facebook on your ceiling and then take the projector into the kitchen and watch the news on the wall. What’s more, these things are incredibly robust, so you can give them to the kids without a worry.”