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FrozenGate by Avery

Direct Green Laser Diode Technology Progress

madmacmo,

Thanks for the welcome.

Understand that I more interested in green lasers from the perspective of projection. For example a 510nm laser will look plenty green to the average person, but if you use it as one of 3 primaries, there is no way to get yellow as the 510nm triangle on the CIE Chromaticity chart from my blog shows.

There are other characteristics like light output when turned on for long periods, temperature range, and the like that are more demanding with projection.
 





rhd,

Microvision has been loosing about $3M per month (>$30M/year) for years on end. The only way they have been able to keep doing this is to keep finding people to invest. So you have to look at all their announcement with the view to trying to print more stock.

Microvision's headlines on news releases I find to be very misleading as it implies something much bigger than what is in the text of the release. You have to parse their words very carefully. Most of their "big deals" are simple distribution agreements for their products and in no way constitute and endorsement of their technology by the company. Based on their financial statements, the sell their products to the distributors at a loss (by all appearances, business has become about raising money from stock holders rather than to make profits on selling products).

Microvision uses "laser beam scanning" where the R, G, and B lasers are aimed onto a single mirror that sweeps the combined beam. This concept on the surface sounds simple and efficient, but there are many serious technical problems with this approach that get glossed over. One of these issues is that the lasers have to turn on, off, or analog levels in between at about 100 MHz.

The DPSS lasers commonly found in laser points switch far to slow to be used in laser scanning. That is why Microvision needed the special designs from Corning and OSRAM that would switch faster.

Microvision's problems are much bigger than just the green lasers. They use the green lasers as a scape goat to hide all the other problems. Part of these problems have been and will continue to be outlined on my blog.


rhd said:
I haven't read your blog, but I do have the sense that Microvision is up to some sketchy marketing. I'll tell you why I say that - (snip)


I don't understand what their stumbling block is at this point. Everyone is blaming their financial situation on the delays associated with direct green diodes, but I think that's bologna. If Corning has no more of their tiny DPSS modules to hold Microvision over until direct greens are affordable/viable, then there are lots of other options. Snake Creek has stuff that is as small as the Corning units (LaserHeads) and I've got a little DPSS "pico projector" crystal set that I bought on eBay for $99 that really wouldn't add any substantial bulk, even when coupled with an IR diode.

In other words, if Microvision is in trouble, it's not because of direct greens not being here, it's because they're doing something else wrong, somewhere.
Click to expand...
 
Sounds like microvision is the new meaning of Cr@pio. I admire their effort but some types of technology just aren't going to make it. Using lasers for a projector just might not be the way to go.
 
Super Critical said:
Sounds like microvision is the new meaning of Cr@pio. I admire their effort but some types of technology just aren't going to make it. Using lasers for a projector just might not be the way to go.
Click to expand...

Actually, it's a brilliant way to go because it hugely minimizes the need for optics, and should in theory allow for smaller projectors. The challenge, I think, is getting the power of the diodes higher.

With the Mits300s hitting much more powerful red targets (at lower costs), and the OSRAM Blues hitting 150mW +, using essentially the same part already in the ShowWX, it should be possible to hit closer to 50 lumens (instead of the 20 they're at now).

Though admittedly I'm not contradicting a previous comment - I think it actually might be the case that green is the limiting factor at this stage.
 
I think it is inevitable that all projectors from movie theaters down to the smallest pico projectors will use lasers for illumination. There are so many advantages of laser light for making projectors that they will be everywhere. The likelihood is that the lasers will be used to illuminate a DLP or LCOS device.

The problem is that laser beam scanning/steering with one multi-axis or two single axis mirrors sounds simple and efficient, but it is anything but if you understand the details. Microvision has does a good job selling investors on the concept and has lost over $400 million of its investors money doing so. But the reality is that their projectors are very inefficient, very expensive, and the image quality is very poor. They are now trying to tell investors that direct green lasers will solve everything when in fact the cost and availability of direct green lasers are only one of their many problems.
 
Question -

If they used lasers with DLP instead of the MEMS steering approach, would they still retain the benefit of nearly infinite focus?
 
rhd said:
Question -

If they used lasers with DLP instead of the MEMS steering approach, would they still retain the benefit of nearly infinite focus?
Click to expand...

Yes, panel based (DLP or LCOS) definitely can be focus free with laser illumination. The laser light itself is very high f-number and sort of works like a pin-hole camera in terms of not needing focusing (the image becomes hyperfocal/in-focus a short distance from the projector to infinity).

Unfortunately this goes against everything in one's human experience with non-laser light and lenses. People think that the only purpose of a lens to focus light. I explained this briefly in my paper at SID this year
(paper is at http://syndiant.com/pdfs/SID%202011%20Guttag-Hurley-Mei%2039-1.pdf), the key section is copied below. I am planning on an article to explain this in more detail on my blog.

3. Benefits of Laser Light
One of the hardest things for people (even highly technical ones)
to believe is that Laser+LCOS projectors are “focus free” because
they have a projection lens. In their common experience with
projectors and cameras, a lens is a way to “focus light.” Even after
spreading the light and any speckle reduction, the laser light
remains at a high f-number. The high f-number of the
illumination and the wide angle lens results in a projected image
that is in focus from a very short distance from the projector to
infinity.

The high f-number light means that all the light is efficiently
collected by small, high f-number optics which reduces the overall
size of the projector. This high f-number light also makes building
very short throw and high (100% or more) offset optics, much
simpler as the optics only need to get the light directed to the right
places without having to also work to keep it in focus. The ability to
implement short throw and high offset projection with small optical
components will be important in meeting the form factor
requirements for many mobile applications.


The existence proof is that projectors have been made and sold, including the AAXA L1 that used a Syndiant LCOS panel that are focus free. For example see the video at AAXA Laser Projector.avi - YouTube which briefly shows it being focus free toward the end of the video.
 
Here's for hoping they somehow DO mass produce these. I'd be more than happy to buy a binned low WL green diode. Thanks for the update!
 
Stuff like this:
picocamera-3.jpg

and in fact, this whole page in general:
Insight Media Microdisplay, Display Intelligence
is complete garbage.

To be clear, I think it's awesome that you posted it - I'm not critiquing that. But the content itself is just dribble meant to drum up licensing revenue from utterly useless/imaginary/irrelevent data, presented in what pretends to be some logical categorized presentation. Look: "$2,500 for a single company site license" to use their report.

This is the dummest crap I've ever read. They're projecting (bad pun, sorry) that by 2016, we'll have 7 categories of projector, including "Toy", "Smart Phone Handset", "Consumer Microprojectors", "Presentation Microprojectors", "Hybrid Projectors", "Stand-Alone Picoprojectors", etc etc etc.

That is the most unbelievably arbitrary and fictitious fabricated nonsense that I've seen in a long time. Anyone who even vaguely follows consumer electronics will know that it's a stretch to predict even broad product trends 2 years into the future. Yet InsightMedia pretends to somehow be able to predict minute product line sub-categorization 4 years out? Bologna.

This is the kind of garbage that print media journalists without a shred of expertise in a subject area (but with big old-media budgets) pay the $2500 price tag for so that they can shlep it into their one-column tech-section feature and impress 60 year old baby boomers who don't own computers, but have heard that "electronics is the new thing these days".
 
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madmacmo said:
Morever your Critical Thinking (questioning assumptions, weighing whether a claim is true, sometimes true, partly true, or outright false) is always a welcome contribution!

btw: Welcome Back, and do hope your re-location went well (and just how many time zones are you now from where your were?) :wave:
Click to expand...

Thank you, and thank you!

I'm actually not firmly "back" yet. I'll still be relegated to basically mobile smart-phone internet until Tuesday. Four time zones away. Not earth shattering, but still quite a relocation.

I'm generally really critical of any media outlet that tries to solicit massive amounts of money for their content in-line with the content itself. Check out that page and look for the point where they transition between talking about projectors, and talking about who should purchase their "content" about projectors.
 
Aha RHD! Ok, that explains some of it. I've been 'gone' as well, dead computer and death in the family. (big sigh)... Getting back into the game here, myself, as well...
 
aryntha said:
Aha RHD! Ok, that explains some of it. I've been 'gone' as well, dead computer and death in the family. (big sigh)... Getting back into the game here, myself, as well...
Click to expand...

Sorry for your loss :(

PS - I think you replied to my email, in this thread, lol.
 
My condolenses for the loss.

Good to see you are back. You always have the impressive lasers of all wavelengths.
 
Wow that gizmo is awesome. So the direct green laser diode is on it's way to us and price is on it's way down. Great find +1

Need to spread some more rep.
 
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I asked for a quote for the 510nm 60mw diode, I'm really curious as to what the prices will be... If its not too expensive maybe I'll pick up a few :D maybe if there is quantity discounts a GB?

Anyway I'll let you guys know when they reply
 
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