The Bitstream Blog :: Posts

Gentlemen, start your engines

Hello happy reader,

Today we’re talking about engines. Not the “hemi four four two” sort but other, more modern flavors…Before I get to my main rant today, that of so called “laser TVs,” I wanted to mention tweaking another engine, Amazon’s recommendation engine…I just finished shopping for some textbooks and ended up back on the home page. Their engine threw a couple of additional textbooks at me, not of interest, as well as a copy of the Criterion Collection version of Harakiri. Now that was a spot–on recommendation, as I watched it just last week. I hadn’t seen it in a long while and had checked it out from my library. A very interesting film in all its rich aspects, though not for the meek and mild…

Anyway, I clicked on the Improve Your Recommendations link that appears once you’re logged in, and informed the engine that, yes, I had purchased Santogold’s single,  L.E.S. Artistes, as well as several examples of (semi–obscure) Japanese cinema for myself but I wasn’t interested in all those textbooks I’ve been buying, they were a gift for someone else. So, now you know you can fine tune the engine, it’s really quite useful.

On to the main topic, laser TVs. I know, you’re thinking, “Oy, not another bogus gadget to snag my hard earned dollar!” Well, this one’s a winner and it’s all because of those doggone lasers.

Let‘s digress…LASERs started life as an lower frequency offshoot of the higher frequency MASER, which outputs (M for) microwave radiation rather than (L for) light radiation. Anyway, laser went from costly and bulky lab curiosities to today’s dime–a–dozen status thanks, in part, to the inclusion of laser light sources in CD players. Early players, I remember the first Philips example, were equipped with a gas laser instead of the solid state laser diodes we find now if we dig deep enough.

A couple of months ago, my local SMPTE chapter had the monthly meeting down at Novalux, maker of semiconductor laser “engines” used for illumination. It was a particularly enjoyable gathering and literally an eye opener. Most current TVs use either cold cathode, incandescent or very recently, LED light sources. All of these suffer from one or more major shortcoming, including limited gamut, short operating life, or low output power/efficiency. Laser light engines, on the other hand, can be configured as very pure, RGB light sources with relatively good efficiency due to the extremely narrow output wavelength. Lasers, by their very nature, produce a single wavelength of light, whereas an incandescent light, as a broadband “black body” illuminant, has laughably poor efficiency and short life. Cold cathode stuff, like fluorescent bulbs and plasma displays, also produce narrow frequency output but the frequencies are not always ideal and efficiency is poor. High power blue LEDs, unlike red and green varieties, are relatively expensive and have relatively poor efficiency. The same goes for “white” LEDs, which actually are phosphor–based, sorta like cold cathode. OK, lasers are spendy but, they have everything else going for them.

So, what’s all this have to do with TVs? All modern TVs, with the exception of plasma, OLED and FED, need a light source to backlight or project the digitally generated raster. Think of the flashlight behind the shadow puppet…Most TVs also employ an absorptive “color wheel” to chop the light into RGB, further reducing how many photons actually hit your eye. Novalux is one of only a handful of companies making laser–based “flashlights.” By the way, they are an OEM so, you won’t see their brand floating around the CE universe.

An interesting ability of laser light engines is that each red, green and blue laser can be individually addressable, though that feature hasn’t been exploited as yet as far as I know. Given development time, this means the spectral output, the color, can be tuned in real time. Blacker blacks with bolder, more accurate color and gray scale images…very nice.

What got me on this high horse in the first place was Mitsubishi’s April announcement that they were bringing out a range of laser light engine–based TVs. At the SMPTE meeting I got to compare several conventional TVs with a laser equivalent. The result? Lasers win, hands down.

My rant is done, TTFN!

Share

2 Responses to “Gentlemen, start your engines”

  1. […] Vote Gentlemen, start your engines […]

  2. […] to pocket projectors, not pocket protectors. If you remember, back in July I blogged about laser display engines. At MacWorld, the folks at Microvision demo’d their as yet unreleased […]