For several years we’ve heard the drum beat of the impending take-over of the traditional metal halide LCD / DLP projector lamp by either LED or laser based projection systems.
At this point in time (early 2016) the verdict remains on the side of traditional metal halide replacement lamps.
Using the projector database tool on Projector Central, we get the following number of projectors currently availabe by light source:
- Metal Halide: 5643 (1400 currently available)
- LED: 572 (240 currently available)
- Laser: 83 (74 currently available)
- LED / Laser Hybrid: 56 (all currently available)
Generally, the challenge for LED projectors is brightness. Most of the 240 currently available LED projectors have lumen output ratings less than 1,000 lumens (and most of those under 600 lumens).
For pico and some portable projectors intended for use in very small settings, this range of brightness may be acceptable. But moving LED into conference room and classroom projectors, which demand brightness levels well above 2000 lumens, still seems a goal more than a near-term reality.
Laser projectors can produce significant brightness. They are starting to be used in the digital cinema market. The use of three separate red, green and blue lasers provides outstanding color - an advantage, particularly for cinema applications.
Laser projectors are expensive. Until the price of these projectors goes down, penetrating the large corporate and educational market will be elusive.
Hybrid LED/Laser light engines use a combination of LEDs and lasers for the red and blue light channels. The expense of green lasers, plus brightness limitations, forces manufacturers to use a phosphor disk process to generate the green light. Operationally similar to color wheels in 1-chip DLP systems, a phosphor disk replaces the color wheel. When an electron bream strikes the phosphor, green light is emitted.
The hybrid approach has potential by combining the benefits of LED and laser. However, the phosphor disk technology is new. It is known that the disk will degrade over time. Still in the early stages of use, the expected life of the phosphor remains an open question.
While brightness and expense pose challenges, manufacturers continue to push these technologies forwarded primarily because of the rated life bonanza they offer. Most metal halide lamps last between 1500 and 3000 hours (operating the projector in eco mode can extend the life to 5000 hours or more). By comparison, LED and Laser offer a 20,000 hour life expectancy.
The average professional buyer operates their projector about 33 hours a month. If their projector uses metal halide lamps, they will need to replace the lamp in 3 to 7 years. Assuming LED and laser projectors were available to meet their needs and at an acceptable price, the life expectancy, for all practical purposes, is forever - 50 years.
Classroom projector usage averages about 800 hours per projector each school year. Using LED or Laser systems, the projectors should be able to function for up to 20 years.
Within these extreme projector light source life spans, whether 20 or 50 years, other projector components will likely fail and newer projectors will come on the market. From a marketing perspective, the main sales point will be that a projector could be purchased knowing the light source will likely never have to be replaced.
The end of the metal halide projector lamp may yet come, but given the brightness, initial expense and other hurdles that still exist for LED, laser and hybrid systems, the day of claiming “no lamp replacement required” is still a ways off.
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