Ask anyone whose industry experience dates back to the 1990s or even further back into the 1980s, and they will say that without a doubt one of the most tedious jobs an AV professional could be tasked with involved the setup and calibration of a CRT projector.
These notoriously fickle products produced great black levels, but low brightness levels, and required lots of TLC to say the least. By the early 2000s the electronics industry was transitioning into Texas Instruments’ (TI) solid-state DLP technology, and other solutions such as LCD and LCoS, which were rapidly maturing to put CRT out to pasture.
Over the past few years, developments in the projector industry have maximized the potential of lamp-based light sources, including brightness levels and lamp longevity. Picking up on where lamp brightness, as well as color gamut potential, and overall product lifespans leave off, today’s LED and laser-based light engines products have boosted efficiency beyond lamp-based products.
Inconspicuous Transition to Solid State
The shift from lamps to technologies such as LED (light-emitting diode) and laser did not happen overnight. Perhaps the troubles of the economy or even the 3D fad hindered the evolution of these technologies, but once LED projectors hit the market a few years ago efforts to finalize hybrid laser products kicked into overdrive.
Now most major projector manufacturers offer laser and LED products. Curtis Lingard, product manager for Christie Digital, says that more than anything it was market demand that drove the development of LED and laser light engines.
“Like most technology developments, the solid-state illumination [SSI] systems were spurred by customer needs. Customer want to maximize their return on investment and they want the best possible performance available, but at the same time, they are trying to minimize their cost of ownership,” he says. “Consumables like lamps have always been a pain point for customers. They have to send a tech out to replace them, stock inventory so they’ve available on demand and, in some cases, the projector is located in a hard-to-reach location so even getting access to the projector to change the lamp can be a challenge. Solid-state illumination helps reduce the overall cost of ownership and reach points that fit most budgets.”
In a whitepaper on the benefits of laser technologies, it explains that pure laser, which is also known as 3-Primary (3P) or RGB laser, generates light directly from three individual red, green and blue lasers. Christie notes the main benefit of RGB laser is its ability to deliver high brightness, along with extended color gamut and broader dynamic range when compared with lamp-based products.
Christie adds that another form of laser, which is known as laser phosphor illumination, uses a blue-laser diode as the light source instead of a lamp. To generate color, the blue-laser diode shines onto a phosphor wheel to create yellow light. Some blue light is allowed to pass through an opening until it hits a diffusion window, while the projector sends the yellow light through to a color wheel to produce red and green. The red, green and blue colors are then sent to an imaging surface like a DLP (digital light pro-cessing) chip that beams the light through a lens and onto a projection screen.
A third laser-based solution is a laser-hybrid projector that uses a similar design to a laser phosphor solution, but it adds a second and even third light sources — usually LED — to augment the amount of red the projector produces.
Explaining LED, Lingard says the technology offers good image quality, stability and reliability, and when it is paired with DLP, it presents a wide color gamut and excellent color saturation. “This helps deliver images that are closer to reality than traditional lamp-based projectors,” he comments. “LED projection has been very popular in simulation, visualization, control rooms and small, fixed installations.”
Many Still Rely on Proven Technologies, Too
Before writing off lamp-based products it is important to note the projection market is drawing distinct lines based on usages, maintenance and brightness requirements that are helping dealers to specify products that fit the exact criteria of their clients.
Neil Wittering, product marketing director for Barco, emphasizes that lamp-based products are still an important part of the overall market. Wittering points out the initial cost of laser products is too much for many buyers, and even with all of the advances happening with lasers, lamp products are also getting better, too.