Laser flashlight

idleprocess

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Laser headlamps have been a slow-rolling train. They're similar to LED in the sense that a blue source pumps a phosphor that converts the tight spectrum of the pump to a more useful broad spectrum of light.

There are a few advantages of laser:
  • The phosphor target can be smaller and more point-like than conventional LED, which is ideal for automotive applications where tight control of the light is important
  • Lasers can be readily - and rapidly - scanned to multiple phosphor targets to selectively illuminate various regions of the beam

There are of course downsides to laser:
  • Cost - laser diodes are inherently expensive
  • Low efficiency - that considerable upfront intensity comes at the expense of far lower electrical efficiency
  • Phosphor lifespan - pumping the phosphor target at the levels that laser headlights are looking to hit could lead to replacement at halogen headlamp-like frequencies

If you want a laser flashlight those have been available for several years now from Wicked Lasers - just look for "phosforce". It's an accessory for one of their blue laser models - phosphor target and reflector that fits over the aperture. The downside is that you need a $200 blue laser that presents a hazard to you and especially anyone within range in 'native' use.

Another technology that's moving along at a potentially faster pace is the concept of using a more general LED (or even laser) light source illuminating a micromirror array. Coupled with an otherwise fairly conventional projector optic frontend, this allows the projection of an arbitrary image in front of the vehicle. One could certainly do static lowbeam/highbeam images, but the idea seems to be to achieve some of the dynamic lighting tech demos we've seen that have previously used large-scale moving parts in order to allow for peak beam intensity at all times with cutouts for oncoming cars, pedestrians, and even raindrops/snowflakes with a good machine vision system continuously analyzing the situation. The maximum area that could be illuminated can potentially be quite wide without requiring any moving parts besides the micromirror array.
 

PhotonWrangler

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...Another technology that's moving along at a potentially faster pace is the concept of using a more general LED (or even laser) light source illuminating a micromirror array. Coupled with an otherwise fairly conventional projector optic frontend, this allows the projection of an arbitrary image in front of the vehicle. One could certainly do static lowbeam/highbeam images, but the idea seems to be to achieve some of the dynamic lighting tech demos we've seen that have previously used large-scale moving parts in order to allow for peak beam intensity at all times with cutouts for oncoming cars, pedestrians, and even raindrops/snowflakes with a good machine vision system continuously analyzing the situation. The maximum area that could be illuminated can potentially be quite wide without requiring any moving parts besides the micromirror array.

This sounds a lot like a DLP projection system. Assuming that the micromirror array could be adequately shock mounted, this seems achievable using existing technology. And as a side benefit, you could park near a light-colored building and use your headlights to project movies on the wall. An instant drive-in theater wherever you go.
;)
 

idleprocess

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This sounds a lot like a DLP projection system.
It pretty much is. DLP being a Texas Instruments trademark I chose a more generic term.

Assuming that the micromirror array could be adequately shock mounted, this seems achievable using existing technology.
I've seem trade show demos on youtube. Think at least one manufacturer has used it in concept vehicles already.

And as a side benefit, you could park near a light-colored building and use your headlights to project movies on the wall. An instant drive-in theater wherever you go.
;)
Only downside is the 1-bit color depth.
 

Zunkted

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Acebeam is making some. They are the WL10 and the WL20 but they are not released yet though.
 

Przemo(c)

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Thanks for your replies. I was just wondering - What's the future of the flashlights, let's speculate for some time :)
A while ago I have asked the question on this forum if we could reach a 1000 lumens out of 1 3.7 v battery and was nearly laughed out of the room and today just look around...
I was thinking what the flashlight world would look like in the next 10 - 20 years? Comparing to what we had 20 - 30 years ago I would guess that we would have something like Maxa Beam capability (range and beam focus option) but packed in 3 times smaller size and 10 times cheaper. Also much more energy efficient. LED or laser, of course, as incans and HIDs will become obsolete.
Your thoughts?
 

lightfooted

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Well I think that whatever we are capable of in the next few years or far off in the future will depend on whether or not the manufacturers have to pay anyone for the right to make it. Patents ensure the designer gets the jump on the market, not that there is a market for it to be in.
 

idleprocess

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I was thinking what the flashlight world would look like in the next 10 - 20 years? Comparing to what we had 20 - 30 years ago I would guess that we would have something like Maxa Beam capability (range and beam focus option) but packed in 3 times smaller size and 10 times cheaper. Also much more energy efficient. LED or laser, of course, as incans and HIDs will become obsolete.
Your thoughts?

There are evolutionary changes to be expected:
  • LED technology has improvements coming down the pike. System efficiency is already hitting 200 lm/W with a theoretical maximum component efficiency of ~348 lm/W. We might see the 300 lm/W components reach production ... or we might not. There's no other technology that's approaching LED efficiency and there are other avenues for improvement such as thermal ruggedness, output sag, tint shifts, green efficiency (although Philips solution has been to use blue-pumped green lately)
  • Battery technology - that perpetual Achilles Heel of flashlights and pretty much all mobile electronics - is likely to see some incremental improvements as well. Li-ion is broadly considered to be played out in terms of improving it, so we're now waiting for new chemistries. At any one point in time there are a dozen or more lab contenders vying to replace the various li-ion chemistries - most of which will fizzle out in the lab for varying reasons of performance, cost, durability, fragility. But if the past is any guide there's reason to believe that there's something better than li-ion coming in the next 10-20 years.

I guess the real interesting question is what revolutionary changes can we look forward to in the future? If I knew the answer to that question I'd be quietly making investments...

Laser-pumped phosphor could be the new thing in 10-20 years. I gather that the blue diodes have been seeing steady improvements in efficiency and cost reduction. There could be solutions forthcoming to phosphor wear or use of optics to spread that intense light out over a larger area whenever a point-like output is not needed.

Incandescent could make a return. There has been ongoing research to greatly improve its efficiency through novel materials-science changes to the filament to convert the heat filaments produce to heat. These approaches were too little too late to save the incandescent general-purpose mains-powered light bulb from efficiency mandates but if they pan out we might see LED-like efficiency from simple, cheap filaments.

Back to LED, if they can make them thermally tolerant to the point that heatsinking becomes somewhat optional, I wonder if we'll see the return of the showerhead format of sorts. It's possible to envision an array of tiny LEDs numbering in the dozens or hundreds in a small area in an arrangement not unlike the compound eyes of an insect with LEDs covering 'sectors' and varying output patterns. The versatility of such a device would be immense - "digital zoom", pan/and tilt beam, colored elements could tune the tint/CRI, already-cheap smartphone sensors could maintain relatively consistent beam orientation as the device is moved, etc. Since no single LED die will be expected to 'carry the show' they can be sufficiently small to pull this off.

Fuel cells might become practical for small electronics in the future. I doubt that the much-pined for hydrogen fuel cell will fall into this category, but perhaps methanol or other types will overcome some of their operating orientation / operating temperature / energy-density / cost / etc challenges and become practical portable energy sources.

Outside of the light-producing side of things, 3D metal printing is becoming cheaper. A number of patents in the field will have expired within 20 years and if the explosion of FDM plastic printing in the last decade immediately after those patents expired we can expect to see immensely cheaper / more accessible metal printing options. This will be quite interesting because presently flashlight design is very much centered around machining which prefers certain symmetries and clearances for either rotating the body against a tool in a lathe or inserting a rotating tool into the body to relieve the material in a mill. Once simply depositing materials becomes practical and affordable, expect the entire design language of flashlights - and countless other metal objects - to change dramatically.
 
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idleprocess

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Preliminary W10 specs look to be out...
http://acebeam.com/w10

• 250 lm, 3° beam
• 5.1Ah 21700 cell
• 3.3 hours runtime
• $300 MSRP

By my quick math that's <50 lm/W. Allegedly throws 1000m so that's something. But also suggests lasers have a little ways to go before they're to be taken seriously as lighting technologies.

EDIT: Now that I'm at a computer, the differences between 21700 and CR123A are striking:
21700 : 5.1Ah * 3.6V = 18.36Wh / 3.3hr = 5.56W or 1.55A. 250lm / 5.56W = 44.93 lm/W
CR123A : ~1.4Ah * 6V = 8.4Wh / 1hr = 8.4W or 1.4A. 250lm / 8.4W = 29.76 lm/W

Presumably the power circuitry is optimized around the 21700 cell, so those numbers are likely a bit more correct ... or as correct as preliminary spec sheet numbers get. The spec sheet is slightly contradictory, with one reference to 300lm / 4.8Ah that I ignored since 250lm / 5.1Ah figures are mentioned twice.

There's likely to be a niche market for this because it's new and Because Lasers™, but otherwise I don't see it going very far (haw!) as priced. Cheaper, more efficient, or some other feature/capability not hinted at seems necessary - i.e. actually throwing a kilometer without breaking a sweat; on that point they mention 0.25 lux in conjunction with peak beam intensity which isn't promising.

In terms of laser flashlights themselves, I suspect they've got a steeper hill to climb than power LED did. Blue laser diodes strike me as a reasonably mature technology after a decade-plus of Blu-Ray players being on the market and unlike LED will likely not be driven to make rapid efficiency improvements by the flashlight market and surely not the general lighting market. Automakers deploying with the concept are likely interested in maximizing output, hitting acceptable lifetimes, and reducing cost well ahead of efficiency improvements - and since they're already better than halogen efficiency possibly not at all.

But I've been wrong at least once before.
 
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night.hoodie

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There are evolutionary changes to be expected:
LED technology has improvements coming down the pike.

I recall seeing that something like Moore's Law predicted LED technology would reach its maximum possible efficiency by 2020.

System efficiency is already hitting 200 lm/W with a theoretical maximum component efficiency of ~348 lm/W. We might see the 300 lm/W components reach production ... or we might not.

Ah, maybe that is what I saw... ?


There's no other technology that's approaching LED efficiency

You mean, except for the recent advances in incandescent technology. :thumbsup:

I'm certain LED has a little room to grow for brightness and efficiency, especially in phosphors that provide high accuracy color rendition, as they come up with new stuff and production quality gets better and tighter, but (if not OT) incandescent tech is not irrelevant (nor did anyone say it was). Capacity for incan advancement really is wide open, should there be enough interest in its development, which I would imagine will probably arrive shortly after LED sooner than later bumps into its theoretical maximums. Maybe LED is not destined to stagnate the way processor technology did. Perhaps manufacturers will give up on the Lumens Wars the way processor manufacturers gave up on the Mhz/GHz Wars, and begin to improve and perfect everything else about a flashlight beyond its emitter.
 

idleprocess

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You mean, except for the recent advances in incandescent technology. :thumbsup:

I addressed this later on in the same post:
Incandescent could make a return. There has been ongoing research to greatly improve its efficiency through novel materials-science changes to the filament to convert the heat filaments produce to heat. These approaches were too little too late to save the incandescent general-purpose mains-powered light bulb from efficiency mandates but if they pan out we might see LED-like efficiency from simple, cheap filaments.

I'm certain LED has a little room to grow for brightness and efficiency, especially in phosphors that provide high accuracy color rendition, as they come up with new stuff and production quality gets better and tighter, but (if not OT) incandescent tech is not irrelevant (nor did anyone say it was). Capacity for incan advancement really is wide open, should there be enough interest in its development, which I would imagine will probably arrive shortly after LED sooner than later bumps into its theoretical maximums.

I'm not so bullish on the idea since it's something that's been talked about for going on 20 years but doesn't seem to have gotten too far outside of the lab. The incandescent industry missed the boat a ~decade ago when lighting-efficiency mandates started appearing worldwide. A mere doubling of efficiency - something we've been hearing is just around the corner for a long time - would have kept them in the game for a long time but it didn't happen. There are possible reasons for this besides outright failure of the concept and they all likely center around cost or operational issues - can't be practically produced in volume, too expensive to produce if it could be made in volume, too fragile in operation, lifespan is too short, requires nonstandard handling/operating conditions, whatnot.

These problems could be solve-able with time. But like so many battery and energy-storage advances the tech press reports on after initial papers they seem to be exclusively lab beasts at this time. It is an attractive concept since the strength of the incandescent is that it's so cheap to manufacture; eliminate the primary weaknesses (high operating cost, low efficiency) and you have a pretty ideal light source even if it's still prone to burning out every 1000 hours or so.

Maybe LED is not destined to stagnate the way processor technology did. Perhaps manufacturers will give up on the Lumens Wars the way processor manufacturers gave up on the Mhz/GHz Wars, and begin to improve and perfect everything else about a flashlight beyond its emitter.

Processors are stagnating because devising new semiconductor processes has become Hard™; witness the industry's struggle with <22nm. Conventional UV lithography is running into hard limits on its abilities to churn out ever-smaller features because of its wavelength. Extreme UV litho has been in development for at least a decade but doesn't seem to be too much closer to practicality due to the challenges of working with such short wavelengths that are so destructive to whatever matter it comes into contact with, the cripplingly low efficiency of its optics, the energy requirements, and other challenges. Note that we've yet to run up against fundamental physical limits of silicon since computing can be done at incredibly subtle levels so long as one can fabricate the devices and amplify their work products in order to produce meaningful physical expression outside of the processor. Assuming that new production processes get sorted out, we'll eventually reach the limits of conventional semiconductors ... but perhaps by then we'll have quantum computing figured out.

We don't know the lower bounds on how many joules it takes to produce a gigaflop nor how many transistors such a metric demands. But we do know some of the limits on the lumen - a pretty rigorously defined physical unit. We know how many photons per second at what wavelengths are in a lumen and we also know how much energy is embodied in those photons, thus can define an upper limit on a light source's efficiency.
 

bykfixer

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Folks are working on some laser tech for military purposes. Dust spec size LED's are also being developed as part of that.
And as we all know, many consumer advances began as military ideas.... barb wire, iron clad ships, machine guns, laser sights etc etc.

Maybe someday super cap technology will gain a foot hold so recharchargable batteries can be refueled in seconds instead of hours.

So with a bunch of dust speck LED's in a die using optics for photon transmission combined with super cap fuel cells.... who knows?

And there are scientists working on nano mirrors to magnify output from nano filaments. Also scientists are working on technology to recycle heat by filaments into light. It is written in an MIT article that the new bulb idea is at 30% efficiency already. It's brightness that is slowly being developed.
Light bulb'd lasers? Methanol fueled batteries? Space Force?
Time will tell.
 
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