For customers, laser-illumination provides several benefits (see below) over lamp-based projections; however, it’s important to understand some of the differences between these new systems. It has been successfully introduced in a number of markets, including digital cinema, where it is rapidly replacing the traditional lamp based approach used for projection due to lower cost of ownership and replacement when compared to xenon-based devices. Currently, LED & lamp based technology are being used that would ultimately pave the way for LASER based illumination.
Types of Laser technologies
Laser Illumination involving Color Wheels: The industry was introduced to color phosphor based illumination that solved the problems of a lamp-based illumination by making use of a blue laser to excite segments of a phosphor quoted color wheel to impart color to the image. This implementation is being currently used in Digital Cinema and certain manufacturers are also using the same in ProAV projectors. The use of Color Wheel based illumination technology involving lasers offers the following advantages over the conventional lamp based technology.
a. Increased brightness levels
b. Higher lifetimes when compared to lamps
c. Lesser no. of replacement cycles
d. Low inventory levels
Laser Illumination with Direct Laser Illumination: The other technology avoids the use of color wheels to impart color and is touted as the “golden standard” in the projection technologies today. It primarily builds on the fact that there are no mechanical parts like the phosphor color wheels that are not meant for 24/7 applications and have a far limited lifetime, making them unsuitable for 24/7 applications. Generally speaking, the color wheel approach is an advancement for the lamp-based illumination, a scenario that does not exist in 24/7 control rooms. The 24/7 control rooms adopted the solid state technology, based on LED illumination years ago. The use of direct laser illumination is a successor to the LED illumination technology, that offered lifetimes in the range of 7~9 years.
Additionally, a critical drawback of the color wheel approach is the precise uniformity and color matching that is required for a video wall deployments where each display device has to blend together giving a perfectly uniform and precise image. This is not the case with direct laser illumination where color uniformity and saturation are Best-In-Class and require very less time for calibration, making deployment and installation much faster when compared to color wheel based implementations.
Benefits of Direct Laser Approach
For critical 24/7 infrastructure , the use of color wheel based approach is not suitable due to high dependency on the use of color wheels which by themselves are prone to failure after a few years leading to in critical business continuity. The direct Laser illumination improvises over the use of LED’s that have for more than 8 years been used in critical 24/7 application. The use of direct laser illumination brings a host of benefits to system integrators, operators and customer alike.
- Very long lifetimes in excess of 9 Years.
- Generic increase in brightness by a factor of 2x.
- Higher Efficiency
- Lower Power Consumption
- High color saturation
- Precise focus
- Unmatched color uniformity.
To conclude, while the ProAV & the D-Cinema are transitioning towards the Color Wheel based approach to do away with legacy lamp based issues, the future clearly belongs to direct laser illumination that would set the benchmark.
Editor’s Note: This article first appeared in Systems Integration Asia Jun-Jul 2016 issue.