Lenovo’s STMicro Based Prototype Laser Projector (part 1)

Lenovo Tech World Projector 001At Lenovo at their Tech World on May 27th 2015 showed a Laser Beam Scanning (LBS) projector integrated into a cell phone prototype (to be clear, a prototype and not a product).   White there has been no announcement of the maker of the LBS projector, there is no doubt that is made by STM as I will show below (to give credit where it is due, this was first shown on a blog by Paul Anderson focused on Microvision )

ST-720p- to Lenove comparison 2The comparison at left is base on video by Lenovo that included an exploded views of the projector and pictures of STM’s 720p projector from an article from Picoprojector-info.com on Jan 18, 2013.   I have drawn lines comparing various elements such as the size and placement of connectors and other components, the size and placement of the 3 major I.C.’s, and even the silk screen “STM” in the same place on both the Lenovo video and the STM article’s photo (circled in yellow).

While there are some minor differences, there are so many direct matches that there can be no doubt that Lenovo is using STM.

The next interesting to consider is how this design compares to the LBS design of Microvision and Sony in the Celluon projector.   The Lenovo video shows the projector as being about 34mm by 26mm by 5mm thick.  To check this I took the a photo from the STM to CelluonTO SCALE  003Picoprojector.com
article and was able to fit the light engine and electronic into a 34mm by 26mm rectangle arranged as they are in the Lenovo video (yet one more verification that it is STM).   I then took a picture I took of the Celluon board to the same scale and show the same 34x26mm rectangle on it.   The STM optics plus electronics are 1/4 the area and 1/5th the volume (STM is 5mm thick versus Microvision/Sony’s 7mm).

The Microvision/Sony is has probably about double the lumens/brightness of the STM module due to have two green and two red lasers and I have not had a chance to compare the image quality.   Taking out the extra two lasers would make the Microvision/Sony engine optics/heat-sinking smaller by about 25% and have a smaller impact on the board space, but this would still leave them over 3X bigger than STM.   The obvious next question is why.

One reason is that the STM either has a simpler electronics design or is more integrated and/or some combination thereof.  In particular the Microvision/Sony design requires an external DRAM (large rectangular chip in the Microvision/Sony).    STM probably still needs DRAM, but it is likely integrated into one of their chips.

There are not a lot of details on the STM optics (developed by bTendo of Israel before being acquired by STM).   But what we do know is STM uses separate simpler and smaller horizontal and vertical mirrors versus Microvision significantly larger and more complex single mirror assembly.  Comparing the photos above, the Microvision mirror assembly alone is almost as big as STM’s entire optical engine with lasers.   The Microvision mirror assembly has a lot of parts other than the MEMs mirror including some very strong magnets.  Generally the optical path of the Microvision engine requires a lot of space to enter and exit the Microvision mirror from the “right” directions.

btendo optics

On the right I have captured two frames from the Lenovo video showing the optics from two directions.  What you should notice is that the mirror assembly is perpendicular to the incoming laser light.  There appears to be a block of optics (pointed to by the red arrow in the two pictures) that redirects the light down to the first mirror and then returning it to the second mirror.  The horizontal scanning mirror is clearly shown in the video but it is not clear (so I took an educated guess) as to the location of the vertical scanning mirror.

Also shown at the right is bTendo patent 8,228,579 showing the path of light for their two scanning mirror design.   It does not show the more complex block of optics required to direct the light down to the vertical mirror and then redirect it back down to the horizontal mirror and then out as would be required in the Lenovo design.    You might also notice that there is a flat clear glass/plastic output cover shown in the at the 21s point in the video, this is very different from the Microvision/Celluon/Sony design show below.

Microvision mirror with measurements
Microvision Mirror Assembly and Exit Lens

Shown at left is the Microvision/Celluon beam scanning mirror and the “Exit” Lens.   First notices the size and complexity of the scanning mirror assembly with magnets and coils.  You can see the single round mirror with its horizontal hinge (green arrow) and the vertical hinge (yellow arrow) on the larger oval yoke.   The single mirror/pivot point causes an inherently bow-tied image.  You can see how distorted the mirror looks through the Exit Lens (see red arrow); this is caused by the exit lens correcting for the bow-tie effect.  This significant corrective lens is also a likely source of chroma aberrations in the final image.


All the above does not mean that the Leveno/STM is going to be a successful product.   I have not had a chance to evaluated the Lenovo projector and I still have serious reservations about any embedded projector succeeding in a cell phone (I outlined my reasons in an August 2013 article and I think they still hold true).    Being less than 1/5th the volume of the Microvision/Sony design is necessary but I don’t think is sufficient.

This comparison only shows that the STM design is much smaller than Microvisions and Microvision has only made relatively small incremental progress in size since the ShowWX announced in 2009) and Sony so far has not improved on it much, at least so far.

Karl Guttag
Karl Guttag
Articles: 244


  1. I too would have serious reservations with respect to a laser projector in a mobile phone:

    * Battery life
    * Fragility (what happens to alignment if the phone is dropped? (And it WILL be dropped)?)
    * Un-supervised children looking into the projector lens and hurting their eyes (I can just imagine the law-suits from this one)

    Interesting article, thanks.

    • Mark, thanks.

      You are right except maybe for fragility, the projector should not be any more fragile than the rest of the phone. I was directly told by phone companies that they would not accept anything more than a Class 1 laser output. They have to assume a kid is going to put the phone up to their eye. Laser scanning goes past Class 1 at 1 to 2 lumens past Class 2 at about 20 lumens. I have heard it speculated that there is more laser scanning activity going on in China right now because they are not as worried about litigation.

      While battery life is an obvious issue, a more subtle but more serious issue is dissipating the heat. Without a fan, no holes, smooth case (no heat fins), and glass covering one side (glass is semi-insulating), heat tends to build up. A smart phone with the GPS and data running in high power mode dissipates on the order of 2 watts. You simply can’t add more than another Watt without over heating the OTHER chips inside. The Celloun projector consumes 2.6 Watts putting out a totally black image and 6 Watts putting out 32 lumens, even if STM’s takes half the power and puts out half the lumens the power numbers don’t work.

      Then you get to the other issue of the usability of a low lumen projector, where it is going to be dark enough and what are you going to project onto. The Lenovo piano playing demonstrations in their video were very contrived and would have been better done with a tablet.


    • The title of this article says “Lenovo’s STMicro Based Prototype Laser Projector”… and attempts to review and analyze Lenove’s embedded [in a smartphone] pico projector display engine prototype. In reality, what it does is to compares the Lenove’s pico display engine prototype for embedded version [in a smartphone] with Celluon’s real product PicoP display engine [MicroVision’s technology] for a standalone PicoP projector.

      Right there lays the fallacy and the shallowness of the entire review, and rips open the agenda of the self proclaimed expert… to discredit any laser based pico projection technology.

      Here’s why…

      • A fair comparison is “Apple to Apple” and not “Apple to Oranges”. It is unprofessional to: 1) compare a “prototype” by Lenove with a “real product” by Celluon, 2) compare an “embedded display engine” prototype by Lenove with a “standalone display engine” product by Celluon.

      • By the time Lenove is ready with their embedded pico display engine for a smartphone… MicroVision and SONY will possibly have several iterations of their embedded PicoP Display Engine with smaller foot print, higher lumen and resolution, and always in focus images. That will be the proper time to make an “Apple to Apple” comparison.

      Product launches are often linear: first make the product, second try to sell it, third try to communicate its value, and finally try to make money.

      MicroVision is in the “final stage” of product launch, making money with its mature laser based PicoP projection technology in partnership with Celluon and SONY. MicroVision is practicing what I call Systematic-Marketing, and is on fast track to this process and speed to profitability.

      Lenove, on the other hand, may or may be using MicroVision’s PicoP technology, but it has not even made a product yet… and is several months behind from the first stage to “make a product”.

      • This article was not a “review” but rather to first prove that it was STM’s engine inside the Lenovo and then contrast and compare what was inside the Lenovo to the Celluon.

        What I provided was photographic evidence for the claims and showed how much smaller the STM’s engine was that Microvision. You jump to motivation as if that can change the facts of the article.

        Microvision has been “the final stages” for going on 15 years now. They have only made modest progress in size and power from the ShowWX in 2009 to what is in the Celluon unit. What makes you think that all of a sudden they are going to 5X smaller? If Sony has such an interest, then does the product not have their name on the case and not some small company few have ever heard of?

        The best you can do to try and say I am wrong is to resort to hand waving that Microvision and Sony COULD be working on something better. Microvision has spent to date over $500 million to get were they are today, what makes you think that $10M or $50M more is going to be the breakthrough?

        I know from your blog that you agenda is to promote Microvision’s stock. I have no long or short interest in either Microvision or STM.


      • Karl, you compared the size of Lenove’s “embedded display engine” prototype with a “standalone display engine” product by Celluon. That’s pretty lame comparison… don’t you think.

        Do you know [or even speculate] that standalone PicoP Display Engine [by Celluon] is intentionally made larger [to distribute the weight evenly] and to fit the smartphone size enclosure.

        I’ll say it again…

        “By the time Lenove is ready with their embedded pico display engine for a smartphone… MicroVision and SONY will possibly have several iterations of their embedded PicoP Display Engine with smaller foot print, higher lumen and resolution, and always in focus images. That will be the proper time to make an “Apple to Apple” comparison.”

        I have no agenda… I’m just a very long investor that believes in the future of this [PicoP] technology… and recognizes the speed bumps on the road to success and huge adoption.

        Regards, and thanks for taking interest in PicoP technology.

      • The comparison is valid. I did point out that the Microvision engine used 5 lasers rather than 3 to get high brightness and that would affect the size of the engine by about 25%. But most of the optics and the Microvision mirror assembly would not be affected by the 5 lasers.

        Microvision has been promoting their technology as being good for embedding and this is as far as they have gotten after about 20 years of development and over $500M of investment. So what you are saying is that people should ignore history and factual evidence and instead believe that it is “possible” is will become considerably smaller all of a sudden because you wish it to be so. What evidence other than your wish do you have?

        The bigger problem for Lenovo/STM has nothing to do with Microvision, it is the impracticality of embedding a projector into a cell phone both in terms of the heat generated (the Celloun projector uses 2.6 Watt just to put up a black image and about 6.1W for a white image) and the usability of such a product in normal indoor lighting conditions and the lack of a good place to project an image.

        Your agenda is very clear, you are not seeking truth or a fair comparison, but rather hoping Microvion’s stock will go up. From you blog, you have been wishing this for a long time.

      • Karl… as I said, I have no agenda. I’m just a very long investor that believes in the future of this [PicoP] technology… and recognizes there are speed bumps on the road to success and huge adoption in the future.

        There is an interesting development that may make your entire “Apple to Oranges” comparison irrelevant and mute…

        As the second half of 2015 approaches─ and there is no announcement of F500 as yet, it becomes more and more clear that Lenovo could be the F500 customer of MicroVision that we have been speculating. All the pieces of the puzzle seem to come together as we approach the end of first half 2015…

        • Lenovo is a F500 company. Confirmation #1… F500 company
        • Lenovo has recently [May 2015] announced a Smartphone with built-in pico projector and a virtual keyboard… and it’s called Smart Cast. Confirmation #2… it’s a Smartphone and more.

        • Lenovo’s Smart Cast is a Smartphone with built-in pico projector and a virtual keyboard. Confirmation #3… it’s a Smartphone Product.
        • Lenovo’s Smart Cast seems to be set for launch in the second half 2015 or the first Qtr of 2016. Confirmation #4… scheduled for launched in the second half of 2015.

        • Lenovo’s Smart Cast is using a laser based pico projection display engine similar to MicroVision’s PicoP display engine in many ways but not exactly. Confirmation #5… Lenovo is not using the PicoP Display Engine made by SONY/MicroVision partnership and is developing its own.

        • Lenovo’s Smart Cast pico projection display engine is based on technology developed by its partnership with STMico/bTendo. STMicro/bTendo may have significant laser based pico projection technology IP… but may find themselves with “holes” that can only be filled with technology licensed from MicroVision. Confirmation #6… in order to fast track and not get bogged down with MicroVision IP infringement, Lenovo/STMicro is licensing limited scope technology from MicroVision.

        Bottom Line: Lenovo is MicroVision’s F500 customer that is licensing limited PicoP technology [and will pay royalty] for its smartphone product [Smart Cast] to be launched in the second half of 2015.

        It is important to understand why…

        1) Patents are written in a language that are broad in their scope and coverage that go beyond the intended and the obvious. When writing a patent application for “single” mirror device… a “two” mirror is obvious to broaden the coverage. Its there as you’ll see… where “two” mirror solution is included as “obvious”.

        2) STMicro is MicroVision’s supply chain partner and privy to all of its technology, trade secrets, design features, copy rights, etc… and as such walks a very thin line of “unintended disclosure” and “unintended IP infringement”. Just because STMicro has it [MicroVision’s IP], knows it, and works with it… does not mean they can just use it for their own enrichment. STMicro would avoid conflict of interest by licensing MicroVison’s technology… and I believe that’s what STMicro is doing for Lenovo’s Smart Cast.

        I have reasons to believe, STMicro is developing the MEMS technology for Smart Cast under license from MicroVision. I don’t see any “licensing fee”… but I do hear “royalty” based on shipped pico display engines units.

        Bottom Line…

        “Lenovo is MicroVision’s F500 customer that is licensing limited PicoP technology [and will pay royalty] for its smartphone product [Smart Cast] to be launched in the second half of 2015.”

        And that changes the whole debate into…

        “It is what it is!!!”

        Regards, and thanks for taking your time to review and compare pico projection technologies.

      • Anant,
        Now that we in the final quarter of 2015 are you aware of any updates on the launch of the Smart Cast? You said below that it would be 2nd half of 2015 (for some reason I couldn’t reply to that post). I Googled it but didn’t see any recent information. Also, do you know the flux output (lumens) and laser classification it will have?

  2. Karl,

    You say you have no financial interest in either MVIS or ST. Do you stand to benefit in any way if LCOS succeeds over LBS? Thanks

    • Bob,

      At this time I don’t have a significant financial interest in either technology and I have never shorted a stock. If you read what I have written, you will find I’m skeptical about using pico projector in cell phones and tablets regardless of the technology.

      If you look at what is going on in the market the vast majority of companies doing small projectors are choosing DLP, those doing small headsets are choosing LCOS, those going for near-eye with a very wide field of view are using ~5-inch flat panels, and only Celluon has a product out with laser scanning (with a fractional percent market share). The companies do the serious evaluation keep coming to the same conclusion. What I am writing is right in line with what rational engineers are concluding by and large. There are always some R&D efforts that get some marketing pizzazz by showing laser scanning and the fanatics that follow the LBS company stocks (mainly Microvision) go crazy over them, but it seem to be a semi-religious effort (which is what the main-stream industry thinks as well, only I am about the only one that writes about it).

      I suggest you read what I write rather than ascribing motives to it. You will see that LBS still has a lot of problems beyond the green laser diodes.


      • You have gone from having no financial interest to no significant financial interest and you did not answer my question.

        You are great at messaging data to see what you want. You say Celluon is the only company out with a LBS product with fractional percent market share. The product was just released and everybody knows the limitation was light sources.

        According to you, Rational engineers are coming to the same conclusion. Sony, Macrovision and Celluon must be chock full of those irrational engineers. Irrational, Fanatics, problems… I read what you write, every word because I think it is important to see all sides of the story.

        You on the other hand did not read what I wrote or you just chose not to answer it. So, once again, Do you benefit financially if LCOS succeeds over LBS in the marketplace?

      • Bob,

        I have a long and extensive background in microdisplays mostly with LCOS so as a consultant people would be most interested in my help in that area, if you take that for bias, then so be it. You might consider the “reviews” and press to unbiased, but generally they don’t understand the technology and for the most part don’t understand projectors and just reprint what they are told by the manufacturers and don’t measure anything objectively. I know a lot about LBS and DLP as well and give this information on my blog. When I found fault with head mount displays the people supporting various products also attacked me personally too.

        Celluon is a small company opportunistically selling the only LBS projector on the market. As the only one selling one they don’t need to have much market share of the projector market as a whole. Once again while “laser projectors” have some marketing pizzazz, they have near zero market impact. As far as Sony, companies all the time are messing around with technologies and doing technology demos, it is the Microvision fanatics that blow it out of all proportions. If Sony was really serious they would not be providing the engine to a small company like Celluon.

        I shown/proven that the Celluon unit absolutely does not have 1280 by 720 resolution. This is a FACT and they are being untruthful about their spec.

        The facts are the facts but you don’t want to deal with the facts of what I present and just want to attack my motive. Tell us, what is your reason for being so biased in favor of LBS that you feel you have to attack me? All we know about you is a fake/anonymous ID.

      • I don’t feel like I have attacked, just questioned. My apologies if you feel that way. My reasons for being so biased for LBS are many and none of them will be new to you. Laser Projectors have had almost no market impact is because until now, mass adoption was impossible due to a lack of lasers. In addition, the shortcomings you have mentioned in the past such as brightness and speckle have been hurdles.

        It is my opinion new versions of LBS engines will resolve these issues and light sources are now available to make a meaningful impact in the market.

        You have doubted the viability of the embedded market, I see it another way. I think embedded has not taken of yet because the technologies available in mass up to now have not been well accepted. I believe LBS will be god enough to create the market. I think Sony sees this as well. Unlike you I do not think this is an internal R&D group playing around. What do you think Sony has spent developing a green laser? 30 million to MVIS, follow on component orders, 8 million up front, 8 year agreement, those are facts that you choose to dismiss as R&D games and you refuse to believe that there just may be something here.

        So, perhaps we both don’t want to deal with facts that don’t exactly fit our narrative. But, I still think you dodged my question.

      • Sorry but LBS is always going to be one of those “wait until next year” technologies. What you have right now is a very expensive technology for the amount of lumens and the image quality. It is not as simple as just waiting for the laser prices to come down.

        As I understand it from Microvision’s financial report, Sony’s “up front” was 8 Million over 8 years or 1 million per year and who knows if there are escape clauses.

        I have seen companies waste hundreds of millions of dollars so Sony’s investment is pretty tiny and certainly not “core” to the company.

        I have presented a lot of factual information on my web site but you either don’t understand or don’t want to understand and I’m not going to change what amounts to religiously like beliefs in LBS, but for the person willing to listen to the facts they might learn something.

      • You are wrong, the money was upfront but recognized for accounting purposes of the life of the contract.

        Sorry, but LBS is now and next year. I have listened to your facts, some are very valid and need to be addressed. You on the other hand are not willing to even consider the possibility that LBS will be viable. I think we have exhausted this conversation, good luck to you.

        And you have still not answered my original question.

      • Yeah yeah, Microvision and its supporter said 2012 was going to be the breakout year.

        How about you tell us about you, say your Linkedin profile?

      • Bob,

        Karl won’t answer your original question because doing so would reveal his motives. He certainly has a financial interest in LCoS which is why he has responded by stating that he has no “significant” financial interest. One should certainly take this into consideration when reading his assessment of the competition.

        Another question that he has not answered is why we’ve not seen a laser illuminated LCoS HD pico projector embedded in a prototype smartphone or tablet. Does the height of the engine prevent this? Is heat a factor? I would like to know the answer to this question.

    • Correct again Karl, but that does not mean this is not the year. BY the way, just curious, did you ever answer my original question?

    • Mike,

      I think you need to read the article more carefully and see the pictures with all the points of correspondence between the STM board and the Lenovo video stills right down to the silk screen markings.

      Additionally in the various videos of the Lenovo projector, there are roll bar bands that are indicative of laser beam scanning (LBS). Compound Photonics uses LCOS and for small projectors it uses field sequential color which has a different “signature” when video (you may see color bands or rolling color, but not black/grey bands).

      All the evidence points heavily to Lenovo using LBS by STM. What gives you a reason to think otherwise and what is your point?


    • Sure I have heard of Compound Photonics. They have made a lot of noise for many years and raised (and I assumed spent) a lot of money but as far as I am aware they have never publicly sold a single projector (they have sold some LCOS for near eye display from their Brillian acquisition). They recently changed CEOs, but it is not clear whether this is going to change the outcome. They went through a number of different concepts from big to small projectors and I think their pico projector was going to be a pretty straight forward LCOS illuminated with Lasers.

  3. I have seen an Android cell phone with a scanning laser engine projector. It was very small, about 20 lumens, about the size of iPhone 6. But, the problems with this technology still persist: horrible battery life, eye safety with people wanting to see how a laser works (2″ from their eye – yes, I saw an intelligent technology sales rep. do this for quite a long time), expensive lasers, etc. Since DLP projector phones aren’t selling in volume, I have to presume that it’s still in the perpetual next year phase. That said, HUD in cars is a different story. LCDs are out, DLP is in, other technologies may follow.

    • I can’t quite place which one you are talking about. There have been several phone plus laser projector devices tried.

      You are likely referring to the Qualper Phone being sold in China which looks a lot like an iPhone 6. While about the same width and length it is about 1.67X thicker (11.5 for the Qualper vs. 6.9 for an iPhone 6). This phone uses the same or very similar Sony optical engine as the Celluon and Sony MP-CL1. But like these stand alone projectors, it claims to output 35 lumens (not 20).

      There is also the Sharp Robohon which has a bit of a novel form factor in that it is part of a small robot as well as being a cell phone. This one has about a 20 lumen output and a smaller optical engine. I suspect it has more speckle as I think much of the Sony’s engine optical complexity and size is due to trying to reduce speckle.

      As my articles have pointed out, laser beam scanning has so far NOT proven to be very energy efficient when actually measured. There is a large power overhead in just driving the lasers and controlling the scanning mirror and the green lasers have a poor electrical to light energy conversion efficiency.

      There are the other issues which you mentioned. Up to 20 lumens, a laser scanning projector can be laser Class 2. Between 20 and 100 lumens roughly it will be class 3R and above 100 lumens it will be class 3B or worse. I just don’t see any first world cell phone company risking putting out a class 3R or above product. Using lasers to “illuminate” a panel such as LCOS or DLP can be class 1 up to about 100 lumens because the light is spread out over the areas of the image to there is no tight beam anymore.

      Ignoring the other practical and laser safety issues, the big biggest issue for projectors in cell phones is their lack of practicality in the “real world”. The issues with ambient lighting and what are you going to project onto become paramount. I discussed these issues in more details in; https://www.kguttag.com/2013/08/04/whatever-happened-to-pico-projectors-embedding-in-phones/

      As for HUDs. Today, LCD panels almost totally dominate the market for HUDs with the notable exception of Two Tree Photonics Laser Hologram used in a few Jaguar and/or Rover HUDs (see for example: http://www.rdmag.com/article/2015/11/jaguar-land-rover-introduces-holographic-head-display). DLP may have advantages over LCDs for larger HUDs but I don’t know of any production products with them yet other than in some aftermarket add-on HUDs.

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