Introduction

LIPA Celebrated its 10^th Anniversary in May; having achieved much progress and many milestones.  As an in-person gathering was still out of the question, we held two, two-hour GoToMeeting sessions.  We enjoyed the inputs and memories of about 80 members, past and present; colleagues and friends.  We even had some surprise guests from the earliest days of Laser illuminated projection.

The idea was to bring together many of the industry’s pioneers, visionaries, technologists and LIPA members to review, acknowledge and reminisce about the history and progress, the challenges and future trends of this radically different lighting technology.

The Sessions

The two sessions were divided into 6 topics: The Early Days, Digital Cinema, Technical Breakthroughs, The Regulatory Story, Commercialization Progress, Status and Future Developments. 

We still don’t know for certain when the “first” LIP was contemplated or built, but we all learned a lot more about how early work began.  We had several pioneers from COLOR, an early R&D shop that built and installed demo LIP systems in museums, sports arenas and even to project images of tanks on “disposable screens” at the US Army’s gunnery range…all in the 1990s!!

We learned about the impact of the Cinema industry’s change from Film to Digital, that enabled the use of narrow-band RGB laser light to generate the millions of colors in the Digital Cinema Initiative’s (DCI) specified color gamut.  The DCinema conversion was both a blessing and curse. One the one hand, it provided a solid, if difficult to achieve, global specification and a huge (future) addressable market. This enticed a few intrepid investors to “go back into” laser technology shortly after the telecom bust of 2003. On the other hand, delays in the financing of the Digital Cinema conversion, (indeed, a global financial crisis in 2008-09), greatly delayed the expected time to market for DCinema LIPs.

The commercial availability of Blue Laser Diodes from Nichia and the extensive Laser-pumped phosphor technology from Appotronics both accelerated DCinema development and enabled a host of new, lower lumen LIP segments and applications.

Although the focus of the sessions was on Laser technology, LIPA founding members, TI and SONY provided the essential Spatial Light Modulator (SLM) technology that enabled the application of Laser illumination to high performance projection.

LIPA’s core mission, in fact its “raison d’être”, is to rationalize global Laser safety regulations to assure risk mitigation while not unduly impeding the adoption of the technology.  The audience learned what a great challenge this was for LIPA, that it took years of meetings and millions in dues and in-kind contributions from members and their expert staff to achieve what would be required for robust commercialization.  LIPA was able to contribute greatly to the understanding of optical hazard and risk; how to quantify it and to establish a global framework that now evaluates laser and lamp illuminated projectors the same way.

Given the magnitude of the challenge and the prerequisite of the US FDA/CDRH to start with a peer-reviewed article on the optical hazards of LIPs, it is (in retrospect), no surprise that it took so long to establish a new and more structured regulatory regime.  In fact, with the help of LIPA’s Regulatory team of member experts, laser safety consultants and yes, lawyers, LIPA adopted a strategy to utilize the International Electro-Technical Commission (IEC) regulatory framework and its updating opportunities to make progress much faster outside of the US. Eventually, with the IEC formally on board, it was much easier to convince the FDA/CDRH to “conform” to new IEC global standards than to start from scratch.  But it still took a long time, and success was never assured.

Ten years ago, high lumen “flagship” Cinema LIPs were demonstrated by several LIPA members. This really put the pressure on LIPA to establish a mechanism to bring these amazing systems into commerce.  Initially, “Laser Variances”, that is, individual FDA authorizations were required to deploy these specialized projectors in large screen, typically 3D-capable theaters.  These early variances provided the template for future global regulatory requirements.

The consensus is that commercialization of Cinema LIPs started with a series of demos and product introductions in spring of 2014 by several LIPA members.  At the same time, the brightness levels achievable with Laser Phosphor technology began breaking records every quarter. People wondered: would they every hit 10,000 lumens…? They did, and have gotten much brighter since.

As of now, LIPs are available at all brightness levels from “Pico” to 75,000 lumens; in nearly every category, from the classroom to the boardroom; from Ultra-Short Throw 4K Laser TV to gigantic, multi-projector mapping systems.  Laser engine architectures now include often complex hybrids of RGB diodes + custom phosphors, optimized for the required mix of image quality, color space, power efficiency and lifetime. 

Market data suggests that LIPs are now the dominant illumination technology on a dollar value (if not unit) basis.  Some major projector makers have moved to all laser or all solid-state illumination, eliminating lamp-based designs from their new product offerings. (Later this year LIPA will publish a formal update on LIP Market penetration.)

The sessions wrapped up with a view to the future.  The consensus was that as the global economy and in particular, Cinemas, “open up”, LIPs will lead the charge.  Many multiplexes were built as or upgraded to “All-Laser” during the pandemic. And many LIPA members have developed new LIP products and product families during the past 18 months. 

LIPA still has much work to do.  As new designs are developed and brightness levels increase, new regulatory cases continue to emerge.  Our long-term mission to assure user safety and promote business success continues, and now that mission covers nearly all projection categories, not just the cutting edge of premium Cinema.

Session Takeaways

1. The development and commercialization of LIPs …TOOK A LONG TIME – at least 30 years.  It took many visionaries, technologists, companies, investors, Hollywood gatekeepers…and LIPA to put all the pieces together.
2. LIPA, founded in May of 2011, by about a dozen companies, developed and achieved a global regulatory rationalization strategy that has enabled very rapid adoption and no known injuries since commercialization of high brightness LIPs in 2014.
3. As of 2020, all high brightness (Risk Group 3) projectors are regulated by the same standard, irrespective of light source technology – Laser and Lamp illuminated projectors are finally on the same footing
4. Over time, LIPs have “paid off” all of benefits of laser illumination, predicted since the 1990s: higher brightness, better image quality, amazing color saturation, ultra-long light source lifetime, higher power efficiency (lm/watt), lower heat generation, quieter operation, remote light delivery via optical fiber and lower cost per usable lumen
5. As a result of the above advances, LIPs have in ten years become the dominant projection illumination technology with a strong trend toward a fully “lamp-less” future.

Introduction

Laser Illuminated Projectors (LIPs) provide both image quality and economic benefits to a wide range of applications.  New laser packaging technology and more sophisticated thermal management subsystems continue to improve the energy efficiency of LIPs for both cinema and non-cinema applications. 

Part of LIPA’s mission is to establish best practices and to educate our members, purchasers and users of LIPs.  With the widespread and growing adoption of Laser illumination, our industry needs a consensus “Figure of Merit” (FoM) by which LIPs can be directly and accurately compared, “in use”.  The goal of this blog post is to propose a well-defined FoM that can provide the basis for comparing, tracking and continuously improving the efficiencies of this increasingly dominant, solid-state illumination (SSI) technology. Furthermore, it will touch on strategies to further increase base efficiencies and extend operating lifetimes.

LIP Overall Energy Efficiency

The Energy Efficiency of a LIP is simply the projector’s output in lumens divided by its wall-plug electrical power consumption. The metric is “lumens per wall-plug watt” or lm/W_Electrical.  This is the most comprehensive and straightforward definition, as it is the measure of what the user “gets” for the quantifiable power utilized (and billed) – at the wall-plug (Mains) source.

This metric should be included on LIP data-sheets, so the customer does not have to calculate it.  It quantifies the efficiency of the projector per se, and allows the user to compare different models and to calculate the hourly power cost to operate the LIP for a given electricity price in $/kW-hr.

Simple yes, but…

This Figure of Merit becomes reliably comparable, when several consensus conditions are met and included in the definition of the proposed metric.

1. The wall plug POWER in watts must include all requisite laser, optics, electronics and cooling, whether on-board (inside the projector) or off-board, in a chiller or radiator.
2. The wall plug POWER in watts includes all the power needed for electronics, processing, fans, content interfaces and storage etc., not just the laser light source.
3. The wall plug power is that which is required to deliver the specified lumens, with the appropriate definition. Examples:  Maximum lumen output; Typical lumen output, Maximum lumen output at calibrated white-point; efficiency at output and power level leading to maximum lifetime.

We see that for any given Projector, one may arrive at different efficiencies levels using the standard FoM [lm/W]. All efficiency values can be valid, comparable and useful if they are clearly defined.

To illustrate how the FoM can be used to compare LIPs in several different modes we can take a hypothetical LIP that delivers a maximum of 20,000 lumens and consumes 2,000W (2.0kW) of wall-plug power to do it.  FoM = 10 lm/W.  When the projector is calibrated for its intended White-point/color space, the output may drop to 18,500lm FoM = 9.25 lm/W.  If the projector is set for maximum operating life, it may produce 15,000 lumens at 1.8kW power consumption FoM = 8.33 lm/W.  The figure of merit is the same, but the value is different when measured and calculated under different operating conditions.

Finally, in comparing operating efficiencies of LIPs, one must also consider the power consumption of any HVAC cooling when the projector’s exhaust heat is “externalized” to the venue operating environment.  For example, the heat dissipation in watts of an operating projector if merely the difference between the wall-plug watt input and the optical power output in watts (not lumens) out of the lens. The design of the projector may seek to maintain a constant Laser (and optics) temperature via the use of a chiller or by air-cooling the whole projector to “the ambient environment”.  In either case, “the environment” still has to dissipate the heat.

In cases where the heat load is large, this cost must be borne either way, but it is NOT included in the Projector efficiency FoM.  Technically, this is true of all LIPs, but for most lower lumen LIPs, the additional HVAC power consumption is de minimis, so can be left out of the calculation.

In conclusion, the simplest efficiency metric, lm/W_wallplug can be used and compared, as long as its measured wall power consumption corresponds to the stated operating condition (maximum, typical, calibrated, average).  In some special cases – ultra-high lumen output and/or ultra-long operating lifetimes, external heat dissipation costs should also be considered in selecting the right projector and operating conditions for the most efficient combination of output level, lifetime and power consumption.

Future LIPA posts and articles will discuss the range efficiency levels and how they are measured and achieved.