Archive for Pico Projection

Sony and Sumitomo

Sorry for being away from the blog so long.  I had two big “consulting gigs” come in one right after the other and I have been working virtually non-stop for the last 6 weeks.  There has been a lot of news come in that period in the area of displays and lasers and I will try and get caught up on some of it.

Today I would like to talk about Sony and Sumitomo announcement of a 530nm 100mW Green laser with 8% efficiency.  At least on the surface, this appears to be a big improvement what Soraa, Osram, and Nichia have announced to date.   But the big question is whether this really changes anything for pico projectors?

Semiconductor laser diode/True green laser emitting

Sumitomo and Sony 530nm Direct Green Laser Diode

Sony was much quieter than Soraa, OSRAM and Nichia but it certainly should have been expected since they developed blue lasers for blue ray (see for example from 2007 “Sony’s Blue Laser Diodes Down to $8 – PS3 and BD Player Price Cuts Soon?”).  Sumitomo had announce they were working on green laser materials back in 2010 but they were not known as a maker of laser diode end products and were thought to be a material supplier (to Sony as it turns out).

Another company to watch would be Opnext who is a leader in red lasers and announced a blue laser diode back in January 2011. All the green laser diode developments I know of came from “stretching” their blue laser developments to get green.

Certainly the Sony-Sumitomo device looks on the spec’s to be significantly better than other companies’ prior announcements with a 100mW, 530nm wavelength (huge improvement over the others), and 8% efficiency.  When you factor in the luminous efficiency at 530nm, they appear to have about double the lumens/Watt of any other green laser announcement I have seen.

Something else to consider, Sony has long been a manufacture of LCOS devices so I would suspect (I have no inside knowledge) that Sony would be looking to couple this laser with their LCOS developments.  They also have the ability to make some very small pixels from their in high resolution LCOS devices.  But the question is whether they and support field sequential color which it necessary for making small embeddable devices.  It should be noted that Sony has a line of  embedded pico projectors in video cameras that use TI’s DLP®

With all this activity and the seeming much improved spec’s from Sony-Sumitomo does this change everything and will laser projectors soon be everywhere?  Unfortunately, I don’t see this as changing things much, at least in the next year few years.

Now the bad news and just based on what they have said.  A 100mW 530nm green laser only supports about a 20 lumen projector which is pretty dim except for a pretty dark room or a very small image. A projector using an 8% WPE green laser probably does not have net an efficiency advantage (after factoring in all the pro’s and con’s) over a good LED projector with at 20 lumens.  While this might have been an interesting product a couple of years ago, the market has mostly moved on to higher lumen projectors.

And then we have to some questions that were not in the release.  Such as how far away is the Sony-Sumitomo green laser diode is from being a product and how much will it cost. Today a green LED to support a 20 lumen projector probably costs about $2. I think there is a serious question as to whether a ~20 lumen project has a value proposition today even if the lasers were inexpensive by the time you factor in the rest of the projector cost.

My bottom line is that it looks like Sony and Sumitomo have made some great technical progress, but it is does not appear to be enough to have a seriously competitive volume product in the market any time soon.    Anyway, that is the way I see it,

Karl

Soothsayer 7: Microvision’s Obfuscations Causing a Buzzing Sound

Microvision continues to make thinly veiled accusations against this blog in their May 9th, 2012 Company Displayground Blog (quoting directly with my bold emphasis added):

Our shareholders are following the topic of direct green lasers with avid interest and we get a lot of questions from them on price and availability. They have ridden the green laser wave with MicroVision and are understandably anxious for their investment and patience to pay off. There is another group of MicroVision watchers that take an active interest in direct green lasers and for that matter, all things MicroVision and have quite a bit to say. We welcome such interest as we are really proud of what our patented solution can do and the advancements we have made with the PicoP Gen2 display technology. But it does get tiring to have an open mic of misinformation from parties who only seem to have an interest in not seeing Microvision succeed. We try and ignore this contingent just like the best thing to do when a fly is buzzing around your head is to ignore it. Eventually the fly finds something or someone else to buzz around and the problem resolves itself.

Like most things Microvision writes they raise more questions than they answer.  For example, who is this “group” of watchers that “ have quite a bit to say” about green lasers?  As far as I know, this is the only blog regularly writing about green lasers for small projectors.   I guess they feel like I have them surrounded :-).   I would suggest that the real reason they cannot ignore the “buzzing sound” is that is goes contrary to Microvision’s attempts at obfuscation and eventually their investors and analysts ask questions.

I take the most interest went key specs are missing or when states what is at best a half-truth.  From what I read, Microvision obfuscates, uses straw-men, half-truths,  give meaningless ratios of improvements, and state goals/expectations as if they have been met.  They could put this all to rest if they could be specific about what they consider “misinformation” and give direct clear answers.  

$200 Green Laser Clarification:

Microvision’s blog when on to clarify(?) what Microvision’s Lance Even’s was saying green lasers costing nearly $200 that I address in my April 30th blog.  Quoting directly from the Microvision Blog:

The price of direct green lasers is understandably a topic of speculation since the manufacturers of the diodes have not publicly discussed pricing or even the exact timing of commercial availability. We cannot reveal specifics around these issues, but we can and have stated that we expect the prices of direct green lasers to be significantly less than synthetic green lasers which have cost nearly $200.

Microvision, apparently in response to my blog on the “nearly $200” price of DGL clarified that Mr. Evan’s $200 remark was in reference to the synthetic green lasers.   But note it is only an “expectation” (as in some time in the future) that the prices will be lower.

It is also interesting that Microvision is admitting publicly that the lasers were costing them nearly $200 (or maybe more at some point).  You have to wonder why they went to market with the ShowWX using a $200 laser for projector with only 10 to 15 lumens.  Can you imagine what investor reaction would have been back in 2009, 2010, or 2011 if they knew that Microvision was selling a supposedly high volume consumer product with a $200 laser in it?   My speculation is that unless they agreed to pay $200 for the lasers and buy a lot of them, that they would have had no way to build any product and if they couldn’t show (some pun intended) and that would make it impossible to raise money.   To keep investors on the hook, so to speak, they had to use obfuscation about the cost of lasers (some things never seem to change).  The losses on the ShowWx were essentially marketing expenses to raise money from the “shareholders” that were following the company back then.

They seem to have made the calculation that they needed to loose many millions of dollars on the ShowWx product line in order to keep the investor money flowing in.  Now that they consider those losses in the rear view mirror, they are admitting to them.   I wonder when they will come clean on the cost and specs of today’s direct green lasers.

More Half-Truths from Microvision

One more interesting set of half truths from Microvision’s blog:

We are confident that the manufacturers of the direct green lasers will be able to meet the volume requirements as the market demand for direct green lasers grows, and we expect price to fall accordingly.”

The first half-truth is that “manufacturers of the direct green lasers will be able to meet the volume requirements.”  Yes, this is true today, but only because the volumes will be very low.   Among the reasons is that the price of the lasers will be very high and that they are not currently designed into any high volume products.   Secondly, by laws of supply and demand, if the lasers are expensive few will be bought and thus they will meet the volume requirements.  Thirdly, the growth in the market could be very slow so it would be easy to meet what Microvision “expects.”    In short, Microvision like a politician, used a lot of words to give no real information.

What Microvision won’t admit, I suspect because that would be bad for raising money, is that the direct green laser has so far proven difficult to make due to the physics involved.    Certainly very smart and capable people are working on DGL, but they are not ready in the near future for the high volume consumer products.

Soothsayer 6: Microvision’s Lance Evans “Green lasers alone are $200 each now”

First, sorry for being away so long.  Some family and other matters took me a way and I fell out of the habit of posting.  I am going to try to have at least couple of posts up a week.

My “Soothsayer” series started back in December 2011 when Microvision released an 8-K a very trasparent response to this blog.  In Microvision’s Dec. 19th 2011 8-K they stated ““In the coming weeks we intend to provide a series of posts that discuss direct green lasers in more detail, as well as other business updates. Stay tuned!”

Well, it has been 19 weeks since Microvision’s 8K and there has been pretty much silence from them on “more details.”  Microvision has had plenty of opportunities to add “more details” in the last 5 months but has chosen not to.  They say a “slip in Washington is when you accidentally tell the truth” well maybe Microvision did that today.

In a way, Microvision finally broke the silence with an article today in an April 30th Technology Review article with Lance Evans (a director of business development at Microvision) stating, “Green lasers alone are $200 each now.” Remember this is probably for a green laser that supports on the order of a 15 lumen projector and has a wavelength that is too short (too blue) to be used in a typical projector and it not very efficient in terms of lumens per Watt. These are lasers that are a best useable in a car HUD display and not a batter powered cell phone or hand held projector.

Back in December 2011 Microvision’s 8K stated, “DGLs will be much cheaper than synthetic green lasers at introduction.”  How does this fit with DGL’s costing $200 today? 

The article does day that “Evans expects that costs should fall to a tenth of current levels by the end of this year,” but note the word “expects” is corporate speak for “believe, wish, hope, or dream” because you generally can’t hold them legally accountable for an “expectation.”  What other than a wish causes the direct green laser cost road map to drop from $200 now to one-tenth that cost or $20 in less than 7 months?  Are there people lined up to buy lasers first at $200, then $100, then $50 say to support a 15 lumen projector?  None of this makes any business sense.

Even if Mr. Evans “expectations” come true, and DGL drop by 10x in less than 7 months to $20 by the end of the year (really for 2013 production), is this really a viable business?   By comparison, there are 200 lumen LED base projectors on the market today and the cost of the red, green, and blue LEDs combined cost less than $20 today.   For a 15 lumen LED projector today, the LEDs are more like $3 for the RGB set.  For a pico projector to make it into a cell phone, the cost to the cell phone maker of the whole projector including electronics has to be on the order of $25 or less (just ask any cell phone maker, I have asked many).  You can even come close with even a $10 DGL, no less 20, when you factor in the cost of everything it takes to make a projector including optics and electronics.

I’m a long term believer that eventually all projectors and in fact a vast number of other products will be using lasers.   It is just going to take more than 2 year for the brilliant people at the laser manufactures to figure out how to make the direct green lasers at a cost point that will lead to mass adoption.

Soothsayer 5: Thanks for the “Shout Out” on the Microvision Conference Call!

It’s nice to know that a CEO of a public traded company is following my blog.   On today’s Microvision Conference Call (available for a few days) at 34:16 in the call, Microvision CEO, Alexander Tokman, in his closing remarks gave a “shout out” of sorts with,  “The direct green laser is becoming a reality this year and not 2014 as some led you to believe.

As anyone that has followed Microvision or my blog and my comments on direct green lasers the last few months should know, by “some” he means “me.”   First, he has mischaracterized what what has been written.    What I have written is that direct green lasers will not be practical for high volume applications until 2014 or beyond.

As I wrote Microvision’s “Soothsayer(?)” for their “Number One Question” in  response to me in Microvision 8K’s “false soothsayer” comments:

The real question is whether these lasers will be available at a price point, with a wavelength, and an efficiency that is practical.   I don’t doubt that most if not all the companies will be in production with a green laser in 2012, but what constitutes “mass production” is a different matter.   Nichia already has a 510nm green laser in production, for example, and it might be possible to build a heads up display for an automobile with it (albeit a bit expensive for the purpose), but that is clearly impractical in terms of wavelength, efficiency, and cost for building a high volume battery powered projector.   I also question whether they will be bright enough for a volume product other than a HUD.

Instead of addressing the real issues, Microvision has seen fit to play silly word games with the definition of word “commercial.”   “Commercial” simply means that companies will sell a product with a given spec.  It does not mean the that product, in this case a Direct Green Laser will meet the cost and performance requirements for a high volume application.  The reality is that the “commercial” direct green lasers are going to be available in 2012 (and 2013) are going to be way too expensive and with key performance limitations  for any kind of significant volume consumer products.

Now lets look at the math in Microvision’s timeline.  At 15:50 into the conference call Alexander Tokman talks about their commercialization timeline for a consumer product.    He said they hope to have a company committed by “mid year 2012” and that companies will generally take “6 to 18 months” to develop a product.   If you follow Microvision at all, you will note that Mr. Tokman timelines are usually wildly optimistic, but just taken him at his word with a “start” in mid 2012 and more realistically 12 to 18 months to get a product designed and ready for production adds up to products STARTING to be manufactured (not even high volume) in late 2013 to mid 2014 if (and this is a big if) everything goes according to Mr. Tokman’s hopes.

But given Mr. Tokman’s history of over optimism, this would seem to say that he is really talking 2014 or later; oh but wait, he said in the conference call that it was “not 2014 as some led you to believe.”     So which does his mean?

TI DLP® “Diamond” Pixel

Fig. 1 DLP Diamond Pixel (above) compared to test pattern (below)

TI’s DLP® WVGA (848×480) and WXGA (1280×800) microdisplays use what are commonly known as “diamond” pixels.  This article will explain what these pixels look like, their effect on image quality, and the reason behind diamond pixel.

As a side note: all the pictures of projected images were taken on a Qumi 1280×800 projector using the HDMI (digital) input driven at the “native” 1280×800 resolution to try and give the best possible source image.

Diamond Pixel Organization

Fig. 2 Diamond Pixel Column and Row Numbering

Fig. 2 Show how the “diamond pixels” are organized.  The pixels themselves are square, but they are rotated 45 degrees and fit like tiles in a zig-zag arrangement.  The Columns and row numbering are based on how the memory bit (signified by the red dot in Fig. 2) for each pixel is address.  You should notice that the columns numbering is more spread out than the row numbering.  For a WVGA (848×480) there are 608 columns [roughly 848/sqrt(2)] and 684 rows [roughly 480xsqrt(2)].  Note that if you multiple 608 x 864 you will get slightly more than 848×480 so there are roughly the same number “pixels.”  Details on this organization for the WVGA can be found in the DLP® 0.3 WVGA Series 220 DMD data sheet.   For the WXGA (1280×800) there are about 910 columns by 1136 rows (the datasheet is not publicly available).

Image Re-sampling Effect of Diamond Pixels

Fig. 3 Simplified Diamond Pixel Re-sampling

The image quality issues with diamond pixels comes from trying to “re-sample” (remap) the pixels from a normal square grid to the “diamond grid.  Fig. 3 Show shows a simplified example of the problem.  There are two black pixels labeled “A” and “B” shown.  On the left side of the figure, the green grid shows the normal/square array of pixels and it is overlaid with the the diamond grid in red.  As can be seen pixel A straddles/touches pixels 1 through 5 in the diamond grid and pixel B straddles pixels 5 though 11.   There is no really good way to map the pixels.  If you you just mapped to the nearest pixel on the diamond grid, it would cause severe jaggies, so it is best to re-sample/filter the pixels onto the diamond grid.

On the right hand side of Fig. 3, I did a simple weighting of the areas of overlap to remap the pixels.   Notice how the pixels have blurred out.  Also notice that the two black pixels end up mapping into different shapes in on the diamond grid because their relative alignment between the square and diamond grid is different.

TI’s DLP uses more complex algorithms than those used in Fig 3 that attempt to reduce the blurring by sharping (particularly in the horizontal direction) or allowing more jagged artifacts (in the vertical direction).  Any algorithm/filtering/re-sampling by necessity will be a compromise between jagged pixel artifacts and blurring. 

Fig. 4 below shows a close-up of a series of simple test patterns of a checkerboard, horizontal lines, and vertical lines with a picture of the projected image from a test pattern.    The checkerboard is pretty well obliterated in the DLP’s re-sampling process and you see what is known as a classic under-sampling problem where you see the “difference frequency” or a low resolution version of the repeating pattern.  It is also interesting is that the artifacts are different in the horizontal and vertical direction because they use different re-sampling algorithms horizontally and vertically.

Fig. 4 Closeup of Checkerboard, Horizontal Lines, and Vertical Lines compared to test pattern

Fig. 5 below shows more more of the test pattern (click on image to see all the detail – at the end of this article, I have included the whole the test image used so you can duplicate this test).   The longer lines in the test pattern are suppose to be 4 alternating black and white lines.  Where the 4 line pairs cross there are some strange effects (one of which is circled).   On vertical lines or groups of lines there is the occasional “ghost line” (some of which are pointed to with red arrows); these are as a result of the horizontal filtering/re-sampling process.   Vertical lines generally look a little better but they have that ghosts lines (“sharpening halos”) as a result of trying to keep from loosing sharpness.

The vertical re-sampling process (which shows up in horizontal lines) is much simpler and results in more jagged artifacts and less effective resolution.   You can also see in the dot in the letter “i” in the “8 Point Arial” how a single pixel blurs out over multiple pixels in the diamond grid of pixels.  Notice how all the dots in the “i’s” vary (circled in red) and in the Arial 10 point font the dots in the letters “i” even point in different directions.

Fig. 5 Diamond Pixel Projected Image of Center of Test Pattern

Why DLP Uses Diamond Pixel

The “marketing spin” I have heard for the diamond pixel organization is that it can give perceptively better resolution.  But this could only be true if the source image is much higher resolution than the displayed image.  As the pictures above demonstrate, about the worst case image is to drive the Diamond Pixel with its supposed “native” resolution.

At least one real reason that the TI DLP® uses the diamond arrangement is to try and reduce the projector’s thickness.   DLP’s require “off axis illumination” which means the light comes into the mirror array non-perpendicular to the surface.  When the mirror is tilted “on,” the angle of the mirror directs the light toward the projection lens. The current DLP mirrors tilt approximately +/- 12 degrees and they tilt diagonally (at 45 degrees).

Fig. 6 Light Paths for “Square” versus “Diamond” Pixel Arrangement

With normal/square mirror arrays (left half of FIG. 6) this would mean that for light to go out of the projector the light must come from above or below projection lens.  But in order to have the illumination light come from above or below the projection lens would make the projector much thicker.   This was not an issue for DLP in RPTVs or larger data projectors, but with Pico Projectors, customers care a lot about thickness.   The “Diamond Mirror Solution” was to rotate the mirrors so that the light could be in the same plane (right half of Fig. 6) as the projected image.

Conclusions

While the diamond pixels address the thickness issue, they definitely hurt resolution and cause artifacts and a loss of resolution.  The obvious problem is that a single pixel on a rectangular grid will cover part of at least 4 or more pixels on the diamond grid.  So there has to be some scaling/filtering to map the pixels from the rectangular grid onto the diamond grid.   The DLP ASIC tries to combat this blurring in the horizontal direction by filtering and sharpening.  The vertical processing is simpler and results in more jaggies.

Many of the problems with DLP’s diamond pixel are closely related to the resolution problems of Laser beam scanning that I wrote about in a previous article (see: http://www.kguttag.com/2012/01/09/cynics-guild-to-ces-measuring-resolution/).  Namely, it is the problem of trying to re-sample the original image to fit a grid or scanning process that does not match the original image.  Even if the number of “pixels” is the same, the re-sampling process hurts resolution and causes unwanted artifacts (for those engineers in the audience, it is a classic Nyquist sampling issue).

In optical terms DLP optics are “off-axis” which means the illumination of the display is not perpendicular to the imager.  Off-Axis optics are always bigger and their light path takes up more volume.  The diamond rotation keeps this volume from increasing thickness, but still the volume of a DLP optical engine tends to be bigger for the same F-number and Focal Length optics.   In general, DLP “pico projectors tend to have longer throw ratios (longer focal length lenses) and this may be due to trying to keep the optics from becoming larger.

Appendix

Below is the test pattern used to create the images above on a DLP 1280×800 projector.  To use this correctly, you need to drive the HDMI input of the projector at 1280×800.

I have included a similar test pattern for WVGA (848×480) that can be used with the WVGA DLP projectors like the PK201 or  Microvision’s ShowWX/+/HDMI projectors.  Additionally, I have included a 720p (1280×720) version of the test patter in case you come across a 720p projector.

I would like to thank Paul Anderson for taking the picture of the test pattern on his 1280×800 DLP Qumi Projector that I used in this article.

1280×800 Test Pattern:

848×480 Test Pattern:

720P Test Pattern:

Answering Questions on Laser with LCOS and LBS

Syndiant 720p LCOS Panel

I got asked a series of questions by reader “me_wwwing” after the article Laser with LCOS is Focus Free — Yes Really! that I am answering in this post because I thought they would be of general interest.  I did have to edit a few of the questions for clarity but tried to keep the intent as best I could and I have re-ordered the questions to put what I think are the more interesting questions first.   For background for the reader I need to add that from prior questions and comments, I know me_wwwing to be a fan of Microvision’s laser beam scanning (LBS) so that may color some of the questions and the answers.

Q1. Does Syndiant need to use the same lasers as MVIS [Microvision laser beam scanning (LBS)]?

The simple answer is that LCOS panels can use any of the lasers that LBS can use and can use lasers that LBS cannot use.   LBS puts constraints on both Diode Pump Solid State Lasers (DPSS also known as “synthetic” or “frequency doubled) and for direct diode lasers (DGL).

Answer Part 1: DPSS Green Lasers

First, Syndiant makes the LCOS microdisplays and not the entire optical engine.     A panel (LCOS or DLP) optical engine has a wider selection of lasers that it can use both for direct green lasers as well as DPSS green lasers.   So the quick answer is that it can use any of the lasers that a LBS system can use plus it can use laser types and variation that LBS cannot use.

With DPSS green lasers, panels could use the less expensive to make and much more electrically efficient (generally about 2X the efficiency) slower switching lasers.  The slower switching frequency doubled lasers are capable of greater than 12% wall plug efficiency (WPE) with the desirable 532nm wavelength green.   About the best the fast switching frequency double green lasers ever got to was about 6% WPE.

The slower switching DPSS greens are capable of going to very high brightness; they can be over 10 times brighter than today’s Direct Green Diode Lasers (DGL).   Their electrical to lumen efficiency is over 3X the best DGLs today.   And their cost is lower than DGLs.   But the drawbacks to DPSS greens include the size and the small spectral bandwidth that causes higher speckle.

Answer Part 2: Direct Green Diode Lasers (DGL)

It turns out that there are different kinds of direct-diode lasers as well.  Most notably there are “single mode” and “multi-mode” lasers.

LCOS or DLP can use either the single-mode or multi-mode lasers, but lasers LBS can only use single-mode lasers.   Multi-mode lasers change wavelength, phase, and/or optical polarity somewhat randomly.  The rate of mode changing would look like noise in a LBS scanning process so it is unusable in an LBS system, but in a panel (LCOS or DLP) system the hopping simply gets average out as it is faster than the eye can detect.

Since changing wavelength and phase reduces speckle, multimode lasers have less speckle.  It turns out that lasers naturally want to mode hop, so it is easier (cheaper) to make multimode lasers, multimode lasers are more electrically efficient and multi-mode lasers can be made much brighter/more powerful (in fact, as they make the laser cavity bigger to make lasers more powerful it is hard to keep them from mode hopping).  So panel based projectors have a significant advantage in being able to use multi-mode lasers.

Historically, traditional laser uses such as telecom and interferometry, needed single mode lasers.   But the same coherent light for these applications is what causes speckle, so for panel based projectors you want “poor quality” lasers with less coherency and thus speckle.

Q2. How big is Syndiant Controller?

The Syndiant’s 720p ASIC is currently 9mm X 9mm in its current package, but could be put in a significantly smaller package by reducing the pin count for an embedded cell phone.  The current package has a lot of extra pins for supporting a mix of applications that make it bigger.

Q3. What are the dimensions of Syndiant’s PCB?  The new one or the old one to have a starting point.

Syndiant sells the panel and the driver ASIC and not a PCB per say.  Single SYA1231 ASIC for their 720p is currently 9mm x 9mm includes frame buffer memory and ARM CPU and can be put in a smaller package for embedded applications.    So there really isn’t much in the way of board space for the new Syndiant 720p controller.  Basically, it is just one small chip 9mm X 9mm chip and not a “PCB” per say.

Syndiant’s single small ASIC compares extremely favorably to the Microvision 720p board which has 2 custom ASICS (one about ~11mm x 11mm and the other ~10mm x 10mm)  and an Altera FPGA (~6mm x 6mm)  on it.  There is also a 4th I.C. on their board which is an Intersil laser driver (5mm x 5mm).   The  picture below is from www.technogytell.com with my notes added it:

Microvision "720p" Optics and Driver Board

Totalling up the area of Microvision’s two ASICs and FGPA, Syndiant’s current control ASIC takes about 1/3rd the area and 1/3rd the ICs of Microvision’s 3 chip controller.   Also just looking at all the power conversion circuitry required in the Microvision “720p” board suggests that it needs a lot of different voltages with some significant power requirements and all this adds cost, board space, and power.

Q4. What size diagonal lens (encased) does Syndiant’s displays need to cover the diagonal of the display?  A length too would be nice. old specs are ok to start with [assuming laser illumination]

The diagonal of the “active display” of the older SYL2010 was 0.21”.  It had a 5.4 micron (10-6 meter)  pixel such that an 800 pixel high display was 4.3mm.   The lens would need to be a bit thicker than this diagonal.  For a small high volume product the lens would be cut to a more rectangular than circular shape to reduce height.   So the lens could be about 6 mm thick.   The SSTDC SEE100 prototype engine http://www.picoprojector-info.com/laseno-see100-module-photo  engine’s lens with its barrel was non-optimized (circular) and was about 8mm thick and 8mm long.  An optimize rectangular-cut lens could have been about 5mm tall.

There is nothing keeping LCOS with laser illumination from going below 5 micron pitch (they will eventually get to around 3 micron and perhaps less) for its pixels.   At about 5 microns the active display for a 720p would be about 3.6mm tall.  A rectangular cut lens would then be about 4.5mm to 5mm tall or a round lens would be about 7mm tall.

Q5. Does the dichroic color combiner lens need to cover the surface of the Vibrating Despeckle unit [the answer addresses the broader question of the light combining system for LCOS and LBS]?

No, the light is not significantly spread out before the dichroic color combiners in an LCOS system.  Also the alignment of the dichroic mirrors/filters and the lasers is non-critical in an LCOS or DLP optical engine.

In should note, however that the alignment of the lasers and the dichroic combiners is very critical in an LBS design.  You should note in this teardown picture (picture taken from a laserpointerforums) that I have labeled the two ball shaped optics (pointed to in magenta) used to aligned the red and blue lasers and then glued into place.   The need to critically align the lasers adds cost and quality issues into to the manufacturing process.

Microvision ShowWX (WVGA) Optics

 

Q6. What is the power to run the PCB and the light engine on a Syndiant’s Displays? (SVGA and WVGA).

That really is a complex and involved question and depends on a lot of factors including the optical engine design and the target brightness.  I am also assuming that this is with LED illumination.   With LEDs the lumens per Watt of power tends to go down as the projector gets brighter, that is one of the advantages with lasers, namely that efficiency does not go down with power. 

It is helpful to break the power into two part, the panel and controller electronics and then the illumination and optics.   For low lumen (less than 30 lumen) projectors, the power of the display and its control is a significant part of the overall power (and less so at higher brightnesses).

The Syndiant LCOS display and ASIC for the WVGA or SVGA will usually consumed about 0.4W.   Due to a number of design improvements, Syndiant’s 720p panel and ASIC consume less power while have a higher color field rate and better light throughput than the older WVGA and SVGA devices while having about 3X the pixels.

In the low lumen area of 10 to 15 lumens with a small, 0.21” WVGA or SVGA panel optical companies were able to get about 7 to 10 lumens per LED Watt.    With some power conversion overhead and including the panel and ASIC this mean that you could get with LEDs about 12 to 15 lumens for 2W of power.  While this is still not good enough for the very high volume cell phone applications, it compares very favorably to the ShowWX which takes 4+ Watts for about 15 lumens.

With lasers the efficiency depends heavily on the lasers used and is dominated by the green laser efficiency which is pretty poor with today’s DGLs.   With today’s DGL efficiencies, LEDs will produce more lumens per Watt, but this will change in the future as lasers improve.   I fully expect to see eventually over 30 lumens per Watt with DGL and LCOS because today with the current DGL, they would be doing well to get 3 to 5 lumens per Watt .

Q7. What would be the lumen output from Syndiant’s displays using the new lasers that Microvision will use [this question was edited for clarity].

This is not a simple question as the spec’s on the lasers and how they can be driven have not been finalized.   I’m pretty sure the lasers that Microvision was using “lab prototype” lasers at CES that were being “over driven.”  The best I can answer right now is to give some insight into the lumens per watt that can be expected as the lasers are perfected.

To begin with, the optical throughput for a laser/LCOS engine should be in the 30% to 40% range where for LBS the optical throughput is reported to be in the 55% to 60% range.   But note, this is the part of the system were LBS looks best in terms of efficiency, but this does not tell the whole story.

Where LBS looses in terms of efficiency is in the drive and control of the laser and the MEM’s mirror.    The Microvision MEM’s mirror alone (not including the ASICs and FPGA’s) at WVGA has been reported to take about 0.4 Watts.   Syndiant’s new 720p LCOS Microdisplay and ASIC combined will take less than that.   Then you have all the power of the 2 ASIC’s and the FPGA that the Microvision 720p board requires.    So LCOS starts with a big lead in terms of power just in power of the display and control.

Then we have biggest power wasters for LBS, that of having to analog modulate the laser drive power.   First you have the fact that each pixel in the laser beam scanning process must be analog modulated at very high speed and high speed analog modulation wastes power.

Additionally, most people are not aware that the laser beam also has to be modulated due to the varying speed of the laser sweep.   If you think about it the laser beam horizontal sweep has to accelerate from zero to the maximum speed at the center of the screen and then decelerate to stop at the far side before returning.  To make a solid image appear uniform, the laser drive has to be constantly varying (for a “solid white” image the drive approximates a sine wave).  See such as the Microvision White Paper (a figure from which is copied below) and the excerpt (copied below) from the Microvision patent application”Apparatus and Method for Interpolating the Intensities of Scanned Pixels“:

From US Patent Application 20090213040

Q7. What is the power to run the PCB and the light engine on a Syndiant’s Displays? (SVGA and WVGA).

That really is a complex and involved question and depends on a lot of factors including the optical engine design and the target brightness.  I am also assuming that this is with LED illumination.   With LEDs the lumens per Watt of power tends to go down as the projector gets brighter, that is one of the advantages with lasers, namely that efficiency does not go down with power.

The LCOS display and ASIC for the WVGA or SVGA will usually consume less than ess than 0.4W.   Due to a number of design improvements, Syndiant’s 720p panel and ASIC consume less power while have a higher color field rate and better light throughput than the older WVGA and SVGA devices while having about 2X to 3X the pixels.

In the low lumen area of 10 to 15 lumens with a small, 0.21” WVGA or SVGA panel optical companies were able to get about 7 to 10 lumens per LED Watt.    With some power conversion overhead and including the panel and ASIC this mean that you could get with LEDs about 12 to 15 lumens for 2W of power.  While this is still not good enough for the very high volume cell phone applications, it compares very favorably to the ShowWX which takes 4+ Watts for about 15 lumens.

Q8. Which VGA display panel is best suited for the cell phone market?

I don’t know that there is a “best.”  Right now about the only reasonably high volume embedded panel is the color filter LCOS one by Himax that is used in cell phones for the India and China market.   The performance of these engines is too poor to be used in “first world” markets.   I think many of them are also less than VGA resolution.   They are typically about 5 to 10 lumens with pretty poor color and contrast and use very cheap but relatively large optics.

Personally, I don’t see a big “first world” need for a VGA or WVGA display.   Why bother projecting an image that lower in resolution than the cell phone’s display?   I think the big market will be to projector resolutions that are at least 720p

Q9. Does Syndiant plan on building the Light Engine?

I can’t comment on Syndiant’s future plans, but Syndiant’s business model has been to be a panel supplier.    There are very large number of good optical engine companies in the world so I don’t know why Syndiant would want to change.

Q10. Is Syndiant depending on someone else to make the Light Engine and Syndiant only sell the display panel?

Syndiant makes the panel and for use by many companies.   This allows different companies to make different products aimed at different markets.

Q11. Does Syndiant’s displays need a Vibrating Despeckle unit with DGLs?

It depends on the DGLs.  With the multimode DGLs you can drive them in such a way as to induce more mode-hopping to reduce speckle.   I would expect the there will not be despeckling required with volume production DGLs.

Q12. Does the light coming off the Vibrating Despeckle unit need to cover the homoginizer [a reference to the 3 year old SSTDC optical engine that used a vibrating despeckler]?

In the old SSTDC design with a vibrating despeckler, the light was partly spread before going to the despeckling mirror but not as large as the homoginizer.

 

Laser with LCOS is Focus Free — Yes Really!

Focus Free LCOS+Laser Projection (click for larger image)

Yes, when LCOS panels are used with lasers they can be “Focus Free.”   I have found that even very technical people have a hard time believing this as it goes against one’s everyday experience dealing with “normal” light and lenses.    People assume that the main function of a lens is to “focus light.”  After all, people are used to having to focus a camera lens or with a projector using lamps or LED light.

The optical physics of why it is focus free would take a long technical discussion, but it has to do with the laser light being effectively infinite f-number.  It is analogous to stopping a camera down to a high f-number where the depth of focus become very large.

Hopefully, “seeing is believing.”  I have uploaded a couple of still pictures (click on images for larger versions) and a short YouTube video demonstrating the focus free nature of the a Laseno Projector (sold in the U.S. as the AAXA L2).  This projector used a SYL2010 SVGA (800×600) LCOS plane with a 5.4 micron pixel pitch and 0.21″ diagonal.

For the top picture in this article, I projected the image the ceiling and some crown molding in my house.  This ceiling has lots of angle and different depths to it and with the crown molding in the way there is some obvious depth differences. Of course with the Laseno/AAXA L2 projector, there is no focusing necessary.

Projected at and angle to demonstrate focus free

Projected at and angle to demonstrate focus free (click on image)

For the picture on the left, I projected the image at a skewed angle from the side to cause a range of depths to be displayed.  The problem you have is that while the projected image is focus free, when the laser light hits the screen it looses it high f-number characteristics and thus the camera needs to focus.   By projecting the image on a flat piece of paper and shooting the picture straight onto the piece of paper I was able to focus the camera while demonstrating the focus free nature of the projector.

But perhaps the best way to demonstrate the focus free nature of a laser/LCOS projector is with a video.  I shot a short ~1 minute video where I mounted the projector on a little dolly and pulled it back away from the screen.  There was some shaking as I moved the projector so I stopped occasionally as I moved it it back so you could see it was still in focus.   I zoomed with the video camera in so you could see the detail in the video image.   Note that the camera’s exposures was locked/fixed on the starting frame, so as the image gets larger, it becomes darker by the ratio of the area so as the projector pull back the video gets a little dark.

I would recommend watching the video at 720p and in full screen to see how the focus is maintained.

Focus Free Video Demonstration

Other Information on the Images

The ~2 year old Laseno projector I used for these pictures has a fixed focus lens.   The image become well focused about 8″ from the projector to infinity.

The Laseno projection lens is not of high quality and you will see some serious chroma aberrations in picture as well as some spots having some blur due to the quality of the lens.  Additionally the projector has “100% offset” meaning that it projects through only the top half of the projection lens so that the projector will project upward from a flat surface without having a keystone effect.  Because of the offset projection, the image is best at the bottom of the image (which is from the center of the lens) at the chroma aberrations (color separation) become progressively worst toward the time.

You definitely will see laser speckle in the images.  The despeckle design was low cost and done over 3 years ago and it uses frequency doubled green lasers which inherently have a high amount of speckle.  Most people who have seen the AAXA L1/L2 “live and compared it to the ShowWX have said that the speckle with the Laseno/AAXA L1/L2  is less than that of Microvision’s ShowWX.

Exclusive: New Pictures of Projected Images by Syndiant’s 720p LCOS Panel

I asked my old company Syndiant if I could take some high-resolution photos of their new SYL2271 720P LCOS panel and they agreed.   Below are pictures I took with an 18 megapixel DSLR.  With some cropping due to the camera being 3:2 versus HD 16:9), there are about 13 camera pixels per for each pixel in the projected image).

To be fair, the optics Syndiant was using were clearly “prototype” and not specifically designed for Syndiant’s 720p panel.   In fact, the optics were designed for a larger 720p panel and thus using the smaller Syndiant SYL2271 was pushing the optics as evident from some of the chroma aberrations and the overall ability to sharply focus the image.   So these images should be worse that what will be seen in the final products.  Also the illumination of the panel in the prototype projector was not uniform which causes some color variation across the white test pattern.

Click on the images below to see the full images.  Note if you view it at less than 100% you may see aliasing due to scaling of the 1 pixel wide horizontal and vertical lines.  So make sure you are looking at it at 100% (you may have to click on the + magnifying cursor on your browser to do so).

If you are not used to seeing such large pictures of projected images you will see things that are not visible to the naked eye when viewing them “live.”  Effectively, it is like looking at the projected images with a magnifying glass.

Syndiant 720P Text Pattern Projected Image

Below is a picture I like because it has a lot of color, detail, and skin tones.

SYL2271 Projected Image of Elf

The picture below is one I took in York England.  If you look at the image at 100% in the left hand tower you can guy-wires holding up the flag pole and the spokes in Ferris Wheel behind the tower.  The clouds demonstrate the ability to do smooth shading

SYL2271 Projected York - Find Ferris Wheel Above Upper Left Tower

Below is the 720p resolution test pattern I used for the first image:1280x720 KGOnTech Test Chart

QP Lightpad™ And Future Observations

QP Optoelectronic’s Lightpad appears to me to be an interesting “transitional product” in the evolution the pico projector “use model”.    In this post I am going to comment on what I think they got right and what will need to be improved to make pico projectors more useful.

The Lightpad combines a rear projection screen, keyboard with touchpad, WVGA (848×480) DLP pico projector, and battery that folds up into a thin form factor.   In effect it turns a smart-phone with HDMI output into a netbook (except that is for the currently for a non-jail-broken iPhone which does allow “mirroring” of the phone’s display) .   The phone acts as the computer with all the software on it, but you now have a larger, easier to read screen and a reasonable size keyboard for typing.  The projector can also be flipped around in a front projection mode to give a larger on say a wall or screen in dark environments.

The Lightpad address one big issue I have with the typical pico projector shoot on the wall use model, namely that there is almost never a white wall, in the right place with low enough ambient lighting to be useful.  The “shoot on the wall” use model only seem to work in very contrived demos.   The Lightpad addresses this issue by having a built-in rear projection screen.

The rear projection screen, as opposed to say a sheet of white paper address a very important issue for pico projectors, namely giving sufficient contrast in typical room lighting.   As I discussed perviously about ambient light, even a dimly lit room has 1 to 2 lumens per square foot and a well-lit room has 30 to 60 lumens per square foot.  It turns out that you want at least 10 to 1 contrast for a reasonably easy to read text, so with a 10 lumen or even 30 lumen projector you can’t project a very big image with much contrast on a white screen.   A rear projection screen is designed to only accept light from a certain range of angles behind it and reject most of the random room light coming from everywhere else.  Because of this “ambient light rejection” a rear projection screen will result in higher contrast in the final image.  So the rear projection screen enables lower lumen pico projector to be very usable in brighter room light conditions.

The keyboard on the Lightpad makes typing easy and the touchpad in front seems to integrate well with the touch interface on the front of the keyboard.  Because the rear projection screen is lightweight plastic, it solves the weight and potential breakages issue of carrying around a large LCD screen.   I could definitely see this type of product being useful for the professional that doesn’t want to carry a laptop with them.  As big an advantage as any being that all the software and data on your smart-phone is available to you without needed to worry about sync’ing or buying a bunch of software.

While I like the concept and QP got many things right in terms of functionality, there are both some short, medium, and long-term improvements that will hopefully be made over time by QP Optoelectroncs and/or other companies.

Short Term (Easy) Improvements

The most obvious flaw, one in which QP says they are working on to improve, is the rear projection screen.  In particular, it has a “hotspot” where if you look at the projector straight it is very bright in the center.    The hotspot effect is show in the picture at the left (but please note a camera exaggerates the effect so it is not as bad as the picture shows but still present).

The next issue, somewhat evident in the picture at the top of this article, is the size and bulk of the cables.  Some of those in the picture are associated with power that will not be there in portable use, but still there are some long bulky cables and adapters between the smart phone and the Lightpad.   In my experience, the cables can often take up more space than the pico projector itself. I would make the cables much shorter, smaller, thinner, and they should easily store into the Lightpad.

Medium Term Improvements

With their announcement of the Lightpad, QP optoelectronics also announced that they are working on a 720p (1280×720 pixels) version.    This certainly would be welcome as many of the newer, more advanced, smart phones are supporting 720p and higher resolutions and one of the big reasons to project a bigger image is to be able to see more.   It really doesn’t make much sense to project a large image if it low in resolution.   Having higher resolution would enable more normal notebook like use for applications such as editing and viewing documents, working on presentations, internet browsing, and spreadsheets.

Long Term Improvements

While Lightpad is light and about the size of a pad of paper when closed, it still does not fit in your pocket.  So you are left to have something to carry around. The really big volume potential for pico projectors is in having something that fits in a normal pocket so it can be with you wherever you go.   Improvements in LEDs and laser light sources should significantly reduce the size of the projector and its battery, but then the issue of the rigid screen and the physical keyboard.

Today with 1 Watt, only about 7 to 10 lumens is possible with LEDs and LCOS or DLP including the light source and light modulator (currently laser beam steering is far behind needing about 3 Watts to give just 10 lumens).   Realistically with significant improvements direct diode lasers and incremental improvements in the light modulators, in a few years it should be possible to produce to about 30 lumens per Watt.    If we want an image that covers about half a square foot, about the area of a small laptop LCD, that means we could get to about 60 lumens per square foot.   If the ambient lighting is normal room lighting of 30 to 60 lumens a square foot then we would only have 2:1 or 1:1 contrast and a very washed out image.  So even with major improvements in pico projector technology we will need to look for a dark corner of the room or still want some form of light controlled screen.

To make the screen easily portable it should roll up into something about the length of a pocket pen (about 6 inches long) and less than 1-inch around (about the size of a white board marker).    Making rollable rear screens with good light control and uniform light spreading (avoiding hot spots) is not that easy as generally there needs to be things like a Fresnel lens which wants to be rigid.  3M has developed Vikuity™ rear projection plastic films  that don’t use Fresnel lenses but these are still meant for rigid installation on a glass or Plexiglas rigid surface.  Perhaps something like the Vikuity materials could be made rollable.

While rear projection screens are the obvious approach,  a perhaps better rollable screen approach would be to use a “wavelength selectable” (WS) front screen.   With a wavelength selectable screen, only specific wavelengths of light are reflected and the other absorbed.  Since normal room or sunlight is “broad spectrum” most of the ambient light is absorbed.  The WS coating could be made on thin rollable plastic.  Sony made a rigid form of WS screen called the ChromaVue™ back around 2005.   At the time Sony said that they could make a rollable version with the same technology but it never came to market.  ChromaVue screens were designed to work with fairly broad spectrum projectors using high pressure lamps with color filters.  Unfortunately, manufacturing costs and low volumes of the ChromaVue screens appears to have caused Sony to stoop making them several years ago.   The task of making a WS screen with narrow band LEDs or Lasers should be much easier so I would think that we will see the re-emergence of WS screens in the future.

Virtual Keyboards and Other Input

Inexpensive camera input should enable the elimination of the physical keyboard with the pico projector projecting the image of a keyboard.  The use of cameras for input is becoming commonplace today with devices such as the Microsoft Kinect™.  In fact, many people in the field expect that pico projectors and cameras will commonly be paired together in future application.

In the case of a rear screen projection one technique is to use infrared cameras (CMOS cameras naturally detect infrared) to sense when and where the screen is touched such as with the Microsoft Surface®.  One advantage of the rear screen infrared approach is that it is relatively easy to detect when the screen as been touched.

There are more issues with a front projecting virtual keyboard.   The first of which is that it become very desirable to project the keyboard at a shallow angle so that the project does not have to be so far away from the surface of a table.   The shallow angle also means that the keyboard will not be blocked as much by shadows cast by one’s hands.   The use of laser light in pico projectors will make short throw, shallow angle projection much easier to implement.

A bit of a technical challenge with front projection keyboards is to know when a key has been pressed versus a finger hovering over a key an there is a lot of work going on in this area.   With structured light (for Microsoft presentation on structured light click here)  and/or multiple cameras detecting finger pressing versus hovering is possible.   One can also expect some quicker input like Swype to be employed.

Conclusion

My expectation is that we will see the pico projector evolve from today’s shoot on the wall gimmick/toy to being a really useful product.    I think the QP Lightpad makes a good first step in the right direction.   It is much easier and with faster adoption rates to use already successful user interfaces and use models than to try and create new ones.     At the same time one needs to live within the physics of what is possible, such as how many lumens will be possible in the coming years for a pocket size device.   The technology for virtual keyboards and multi-touch displays is becoming very advanced and should not be a limiting factor.

CES 2012 Pico Projector Overview

As part of my marathon training, I ran 18 miles the Sunday before CES and it turned out to also be good practice for attending CES.   I’d estimate I averaged over 4 miles walking the floor and between venues (it was faster to walk the mile to the Venetian than take a bus at busy times of day) plus my morning 3 mile jog.   For this post, I’m going to give some quick highlights of what I saw about pico projectors at CES.   I plan on writing in more detail about some of these items in in the near future.

Over half of the show hours I was in private meetings that I can’t talk about, but I did get a chance to see and hear about a number of pico projector related activities that are public.   I can’t hope to compete with the many people that give you the quick and glossy news of CES that mostly just repeat the company talking points, but as you should come to expect from me, I will be doings some more in-depth analysis with an engineer’s eye of the products.

QP Optoelectronics introduced their “Lightpad” product at CES.   It interfaces to smartphones with an HDMI output and combines a keyboard, DLP WVGA (848×480 pixel) pico projector, rear projection screen, and battery that easily folds up into a thin and light form factor.

While it is not perfect yet, there is a lot to like about the basic concept and they said they got a lot of interest at CES.   It at least starts to address some of the issues with “use model” that I have written about earlier.  I am working on an article that talks about the good and bad points of this concept and where I see this type of product  going in the future.

Syndiant’s biggest news was their formal announcement of the SYL2271 720P 0.31” diagonal LCOS microdisplay and its accompanying SYA1231 ASIC.   Shown at left is an actual picture of the SYL2271 that has been pasted into some cute artwork.  The Syndiant had three SYL2271 720P projectors running in their private suite all showing 720p HD movie content.  All of the optical engines were very much “prototypes” with some optical quality issues and not near production ready.

Syndiant also jointly announced Viewlink’s new Vizcom™ Wi-Fi Cloud-Connected Near-Eye Visual Communication System.  The VizCom system includes a wearable heads-up display with integrated 720p video camera and an AndroidTM smart controller.  VizCom allows content to be streamed directly to the cloud via built-in Wi-Fi or by 3G/4G wireless smartphones, tablets or cellular hotspots. The Syndiant SYL2010 SVGA (800×600 pixel) panel acts as a camera viewfinder and as a display.  There was a working prototype of the display but not the overall product in Syndiant’s suite.   The optical quality of the prototype optics left something to be desired but the mechanical workings of the headset seemed to be very workable compared to other near eye products I have used.

Syndiant had a demo of a 160 lumen 3-D passive glasses pico projector that used two SYL2061’s with a single projection lens in a light engine designed by ASTRI.   The projector would either present 80 lumens to each eye in 3-D mode or 160 lumens to both eyes in 2-D mode.

A number of Syndiant pico projector products were filling about half of 3M’s booth at CES.   There were several more conventional pico projectors like the older MP160 and MP180 plus a new SYL2061 WSVGA (1024×600) based MP220 with 50 lumens.

Additionally 3M was showing a new “Camcorder Projector,” the CP40, which combines a handheld video camcorder with an SVGA pico projector.

Syndiant based products could also be found at AAXA’s and WSOT’s booths at CES and I expect some other places that I may have missed.  AAXA was demonstrating a new projector based on Syndiant SYL2061 panel.   WSOT has a dual panel WSVGA 3-D passive glasses projector similar to the one at Syndiant’s suite.   They also had a demonstration of prototype projector with a 4cc light engine based on Syndiant SYL2030 WVGA (854×480) device.

TI’s DLP certainly had by far the biggest presence of any of the pico projector display makers; although most of the newer products probably should be called “mini” rather than “pico” projectors.   There were a number products based around their WXGA (1280×800) 0.44” panel with products that were from 1.3-inches to over 2 inches thick.  These products were clearly aimed more at business professionals to put in their briefcases and had marketing spec’s of 200, 300, and some with 500 lumens (note these are often their “marketing lumens” which often are inflated by 1.2X to nearly 2X depending on the brand).

All of these WXGA projectors were really designed for wall plug rather than battery operation and have no internal batteries.  But Vivitek did find a way to make their battery powered by adding large external battery packs.   Essentially these battery packs have DC power cord to plug into the DC jack normally used by the AC wall plug power pack.

There could also be found a number of very similar looking WVGA (848×480) DLP pico projectors at the various booths around the show with light outputs ranging from about 30 lumens to as much as 80 lumens.  Most of these projectors include internal batteries.

DLP Diamond Pixel Arrangement

Both the WVGA and WXGA projectors use what is known as “Diamond Pixels” in which the DLP mirrors are rotated 45 degrees in a tile like arrangement show at the left.  This is done to reduce the thickness of the optics (a complex discussion for another day).

The re-sampling/scaling of the image from a normal square pixel grid to the diamond grid  does have a negative impact with high-resolution computer content.  Click on the thumbnail on the right to see the effects of the diamond pixel scaling on a high-resolution test pattern.

A notable exception to the bigger and brighter DLP projectors and much more of a “true” pico projector was used in Sony’s lineup of 4 camcorder models with pico projectors build into backs of the flip-out LCDs monitors.  These projectors used DLP’s 0.22” diagonal nHD (one-ninth 1080p or 640×360 pixels).   It seems to me to be a mismatch to combine a 1080i camcorder with a pico projector that has 1/9th the pixels.

I was told my multiple companies at CES that TI has a major campaign to get all the makers of LCOS pico projectors to carry at least one DLP based projector.  TI provided all kinds of support to get the projector companies to have at least one DLP product and to a large degree they succeeded with companies including 3M and AAXA showing DLP products along with their LCOS projectors.

Microvision "720P" (click on image)

Microvision was showing a new “so called 720p” multimedia projector at CES.  I say “so called 720p” because they would only demonstrate low resolution cartoon like video games on it.  I did ask them to put up a test pattern to show that they really could do 720p (1280×720) resolution but they politely refused.   My engineering instinct is that if someone is claiming HD resolution, they would be showing off HD content.   I also noticed that the 720p projector seems to be off whenever they were not demonstrating it to someone which suggests that there may be some laser lifetime and/or heating issues with the device.

The prototype media player projector was to me surprising large considering they have been claiming the whole PicoP® concept to be aimed at embedded products.  While the light engine optics itself is about 4cc, by the time you add all the electronics and a very large heat sink/heat spreader underneath the projection engine, about 25cc (56mm x 38mm x 12mm) within the media player are consumed (click on the picture above that shows some of the dimension).  Imagine how much bigger still it would be if had to add the cell phone engine and its LCD/OLED display to the package.  Compared to DLP and LCOS projection engines, there seems to be a large amount of electronics associated with LBS.

The same week as CES, Microvision put out flyer with set of partial spec’s on the PicoP engine itself (less any of the media player features).    To a degree, the spec sheet confirms some serious issues with the whole laser beam scanning (LBS) concept that Microvision uses.  The flyer says that at 15 lumens it will be a Class 2 laser product, but in a footnote it admits that the 25 lumen version would be “Class 3R” confirming what I (and others) have said for years about the issues with laser safety standards with LBS.  Note, the cell phone makers have told me that they wouldn’t put anything beyond Class 1 (considered totally eye safe) into a consumer cell phone and LBS type displays would support less than 1 lumen at Class 1; so even the Class 2 rating at 15 lumens I would consider to be a serious problem.

Another interesting indirect admission in the “spec” is that they consume “Approximately 2.0 Watts” at “27% video.”    It seems like a bad job of trying to hide a power problem.  It begs several questions, most obviously, what is the power consumption at some rated (measured) lumens.  If we assume it is for their 15 lumen projector and simply scale up we get over 7 Watts!   To get a realistic power consumption we have to know how “approximately” the power consumption number is and what it covers in the system.   As I wrote previously about the ShowWX power consumption, they seem to be a long way from their power “goals” to fit in an embedded product.

Another little tidbit from the “spec” is that it only has 16-bits per pixel (64K colors which means they have only 6 bits two primary colors and 5 bits of the third primary).  Most products today have at least 24-bits per pixel (8 bits each of red, green, and blue) = 16 Million colors.   This suggests some limitation in the ability to control the colors with their system.

I will have some more comments on the Microvision 720p as well as their 3-D and hand tracking demonstrations in an upcoming article.

Vuzix Holographic Optics

Vuzix was demonstrating an interesting technology for near eye heads up displays.  They have holograms embedded in a thin piece of plastic that can bend the output of a projector 90 degrees, translate and expand it, bend it back 90 degrees, and have it focused at infinity (so your eyes can stay on the real world).

I didn’t get the best picture of it on the above (it is kind of tricky and I didn’t have much time) but it is impressive how they can manipulate the light using hologram light guides.   While the image is in focus and would seem to be acceptable the intended purpose of a near eye HUD/augmented reality display, the image quality is not what you would want for say watching a movie.  Everything seems to have a “glow” to it which I suspect come from the contortions that are done to the light by the holograms.

That’s it for the “overview.”  Certainly my coverage of CES was spotty and if anything I didn’t give a lot of coverage to DLP relative to the number of products that were at the show.  If you have questions or want more details on some subject, please ask.