Tag Archive for AR

CES 2017 AR, What Problem Are They Trying To Solve?

Introduction

First off, this post is a few weeks late. I got sick on returning from CES and then got busy with some other pressing activities.

At left is a picture that caught me next to the Lumus Maximus demo at CES from Imagineality’s “CES 2017: Top 6 AR Tech Innovations“. Unfortunately they missed that in the Lumus booth at about the same time was a person from Magic Leap and Microsoft’s Hololens (it turned out we all knew each other from prior associations).

Among Imagineality’s top 6 “AR Innovations” were ODG’s R-8/R-9 Glasses (#1) and Lumus’s Maximus 55 degree FOV waveguide (#3). From what I heard at CES and saw in the writeups, ODG and Lumus did garner a lot of attention. But by necessity, theses type of lists are pretty shallow in their evaluations and I try to do on this blog is go a bit deeper into the technology and how it applies to the market.

Among the near eye display companies I looked at during CES include Lumus, ODG, Vuzix, Real Wear, Kopin, Wave Optics, Syndiant, Cremotech, QD Laser, Blaze (division of eMagin) plus several companies I met with privately. As interesting to me as their technologies was there different takes on the market.

For this article, I am mostly going to focus on the Industrial / Enterprise market. This is were most of the AR products are shipping today. In future articles, I plan to go into other markets and more of a deep dive on the the technology.

What Is the Problem They Are Trying to Solve?

I have had an number of people asked me what was the best or most interesting AR thing I saw at CES 2017, and I realized that this was at best an incomplete question. You first need to ask, “What problem are they trying to solve?” Which leads to “how well does it solve that problem?” and “how big is that market?

One big takeaway I had at CES having talked to a number of different company’s is that the various headset designs were, intentionally or not, often aimed at very different applications and use cases. Its pretty hard to compare a headset that almost totally blocks a user’s forward view but with a high resolution display to one that is a lightweight information device that is highly see-through but with a low resolution image.

Key Characteristics

AR means a lot of different things to different people. In talking to a number of companies, you found they were worried about different issues. Broadly you can separate into two classes:

  1. Mixed Reality – ex. Hololens
  2. Informational / “Data Snacking”- ex. Google Glass

For most of the companies were focused on industrial / enterprise / business uses at least for the near future and in this market the issues include:

  1. Cost
  2. Resolution/Contrast/Image Quality
  3. Weight/Comfort
  4. See-through and/or look over
  5. Peripheral vision blocking
  6. Field of view (small)
  7. Battery life per charge

For all the talk about mixed reality (ala Hololens and Magic Leap), most of the companies selling product today are focused on helping people “do a job.” This is where they see the biggest market for AR today. It will be “boring” to the people wanting the “world of the future” mixed reality being promised by Hololens and Magic Leap.

You have to step back and look at the market these companies are trying to serve. There are people working on a factory floor or maybe driving a truck where it would be dangerous to obscure a person’s vision of the real world. They want 85% or more transparency, very lightweight and highly comfortable so it can be worn for 8 hours straight, and almost no blocking of peripheral vision. If they want to fan out to a large market, they have to be cost effective which generally means they have to cost less than $1,000.

To meet the market requirements, they sacrifice field of view and image quality. In fact, they often want a narrow FOV so it does not interfere with the user’s normal vision. They are not trying to watch movies or play video games, they are trying to give necessary information for person doing a job than then get out of the way.

Looking In Different Places For the Information

I am often a hard audience. I’m not interested in the marketing spiel, I’m looking for what is the target market/application and what are the facts and figure and how is it being done. I wanting to measure things when the demos in the boths are all about trying to dazzle the audience.

As a case in point, let’s take ODG’s R-9 headset, most people were impressed with the image quality from ODG’s optics with a 1080p OLED display, which was reasonably good (they still had some serious image problems caused by their optics that I will get into in future articles).

But what struck me was how dark the see-through/real world was when viewed in the demos. From what I could calculate, they are blocking about 95% of the real world light in the demos. They also are too heavy and block too much of a person’s vision compared to other products; in short they are at best going after a totally different market.

Industrial Market

Vuzix is representative of the companies focused on industrial / enterprise applications. They are using with waveguides with about 87% transparency (although they often tint it or uses photochromic light sensitive tinting). Also the locate the image toward the outside of the use’s view so that even when an image it displayed (note in the image below-right that the exit port of the waveguide is on the outside and not in the center as it would be on say a Hololens).

The images at right were captured from a Robert Scoble interview with Paul Travers, CEO of Vuzix. BTW, the first ten minutes of the video are relatively interesting on how Vuzix waveguides work but after that there is a bunch of what I consider silly future talk and flights of fancy that I would take issue with. This video shows the “raw waveguides” and how they work.

Another approach to this category is Realwear. They have a “look-over” display that is not see through but their whole design is make to not block the rest of the users forward vision. The display is on a hinge so it can be totally swung out of the way when not in use.

Conclusion

What drew the attention of most of the media coverage of AR at CES was how “sexy” the technology was and this usually meant FOV, resolution, and image quality. But the companies that were actually selling products were more focused on their user’s needs which often don’t line up with what gets the most press and awards.

 

ODG R-8 and R-9 Optic with a OLED Microdisplays (Likely Sony’s)

ODG Announces R-8 and R-9 OLED Microdisplay Headsets at CES

It was not exactly a secret, but Osterhout Design Group (ODG) formally announce their new R-8 headset with dual 720p displays (one per eye) and R-9 headset with dual 1080p displays.  According to their news release, “R-9 will be priced around $1,799 with initial shipping targeted 2Q17, while R-8 will be less than $1,000 with developer units shipping 2H17.

Both devices use use OLED microdisplays but with different resolutions (the R-9 has twice the pixels). The R-8 has a 40 degree field of view (FOV) which is similar to Microsoft’s Hololens and the R-9 has about a 50 degree FOV.

The R-8 appears to be marketed more toward “consumer” uses with is lower price point and lack of an expansion port, while ODG is targeting the R-9 to more industrial uses with modular expansion. Among the expansion that ODG has discussed are various cameras and better real world tracking modules.

ODG R-7 Beam Splitter Kicks Image Toward Eye

With the announcement comes much better pictures of the headsets and I immediately noticed that their optics were significantly different than I previously thought. Most importantly, I noticed in the an ODG R-8 picture that the beam splitter is angled to kicks the light away from the eye whereas the prior ODG R-7 had a simple beam splitter that kicks the image toward the eye (see below).

ODG R-8 and R-8 Beam Splitter Kicks Image Away From Eye and Into A Curved Mirror

The ODG R-8 (and R-9 but it is harder to see on the available R-9 pictures) does not have a simple beam splitter but rather a beam splitter and curve mirror combination. The side view below (with my overlays of the outline of the optics including some that are not visible) that the beam splitter kicks the light away from the eye and toward partial curved mirror that acts as a “combiner.” This curve mirror will magnify and move the virtual focus point and then reflects the light back through the beam splitter to the eye.

On the left I have taken Figure 169 from ODG’s US Patent 9,494,800. Light from the “emissive display” (ala OLED) passes through two lenses before being reflected into the partial mirror. The combination of the lenses and the mirror act to adjust the size and virtual focus point of the displayed image. In the picture of the ODG R-8 above I have taken the optics from Figure 169 and overlaid them (in red).

According to the patent specification, this configuration “form(s) at wide field of view” while “The optics are folded to make the optics assembly more compact.”

At left I have cropped the image and removed the overlay so you can see the details of the beam splitter and curved mirror joint.  You hopefully can see the seam where the beam splitter appears to be glued to the curved mirror suggesting the interior between the curved mirror and beam splitter is hollow. Additionally there is a protective cover/light shade over the outside of the curved mirror with a small gap between them.

The combined splitter/mirror is hollow to save weight and cost. It is glued together to keep dust out.

ODG R-6 Used A Similar Splitter/Mirror

I could not find a picture of the R-8 or R-9 from the inside, but I did find a picture on the “hey Holo” blog that shows the inside of the R-6 that appears to use the same optical configuration as the R-8/R-9. The R-6 introduced in 2014 had dual 720p displays (one per eye) and was priced at $4,946 or about 5X the price of the R-8 with the same resolution and similar optical design.  Quite a price drop in just 2 years.

ODG R-6, R-8, and R-9 Likely Use Sony OLED Microdisplays

Interestingly, I could not find anywhere were ODG says what display technology they use in the 2014 R-6, but the most likely device is the Sony ECX332A 720p OLED microdisplay that Sony introduced in 2011. Following this trend it is likely that the ODG R-9 uses the newer Sony ECX335 1080p OLED microdisplay and the R-9 uses the ECE332 or a follow-on version. I don’t know any other company that has both a 720p and 1080p OLED microdisplays and the timing of the Sony and ODG products seems to fit. It is also very convenient for ODG that both panels are the same size and could use the same or very similar optics.

Sony had a 9.6 micron pixel on a 1024 by 768 OLED microdisplay back in 2011 so for Sony the pixel pitch has gone from 9.6 in 2011 to 8.2 microns on the 1080p device. This is among the smallest OLED microdisplay pixel pitches I have seen but still is more than 2x linearly and 4x in area bigger than the smallest LCOS (several companies have LCOS pixels pitches in the 4 micron or less range).

It appears that ODG used an OLED microdisplay for the R-6 then switched (likely for cost reasons) to LCOS and a simple beam splitter for the R7 and then back to OLEDs and the splitter/mirror optics for the R-8 and R-9.

Splitter/Combiner Is an Old Optic Trick

This “trick” of mixing lenses with a spherical combiner partial mirror is an old idea/trick. It often turns out that mixing refractive (lenses) with mirror optics can lead to a more compact and less expensive design.

I have seen a beam splitter/mirror used many times. The ODG design is a little different in that the beam splitter is sealed/mated to the curved mirror which with the pictures available earlier make it hard to see. Likely as not this has been done before too.

This configuration of beam splitter and curve mirror even showed up in Magic Leap applications such as Fig. 9 from 2015/0346495 shown at right. I think this is the optical configuration that Magic Leap used with some of their prototypes including the one seen by “The Information.

Conclusion/Trends – Turning the Crank

The ODG optical design while it may seem a bit more complex than a simple beam splitter, is actually probably simpler/easier to make than doing everything with lenses before the beam splitter. Likely they went to this technique to support a wider FOV.

Based on my experience, I would expect that ODG optical design will be cleaner/better than the waveguide designs of Microsoft’s Hololens. The use of OLED microdisplays should give ODG superior contrast which will further improve the perceived sharpness of the image. While not as apparent to the casual observer, but as I have discussed previously, OLEDs won’t work with diffractive/holographic waveguides such as Hololens and Magic Leap are using.

What is also interesting that in terms of resolution and basic optics, the R-8 with 720p is about 1/5th the price of the military/industrial grade 720p R-6 of about 2 years ago. While the R-9 in addition to having a 1080p display, has some modular expansion capability, one would expect there will be follow-on product with 1080p with a larger FOV and more sensors in a price range of the R-8 in the not too distant future and perhaps with integration of the features from one or more of the R-9’s add-on modules; this as we say in the electronics industry, “is just a matter of turning the crank.”

Everything VR & AR Podcast Interview with Karl Guttag About Magic Leap

With all the buzz surrounding Magic Leap and this blog’s technical findings about Magic Leap, I was asked to do an interview by the “Everything VR & AR Podcast” hosted by Kevin Harvell. The podcast is available on iTunes and by direct link to the interview here.

The interview starts with about 25 minutes of my background starting with my early days at Texas Instruments. So if you just want to hear about Magic Leap and AR you might want to skip ahead a bit. In the second part of the interview (about 40 minutes) we get into discussing how I went about figuring out what Magic Leap was doing. This includes discussing how the changes in the U.S. patent system signed into law in 2011 with the America Invents Act help make the information available for me to study.

There should be no great surprises for anyone that has followed this blog. It puts in words and summarizes a lot that I have written about in the last 2 months.

Update: I listen to the podcast and noticed that I misspoke a few times; it happens in live interviews.  An unfathomable mistake is that I talked about graduating college in 1972 but that was high school; I graduated from Bradley University with a B.S. in Electrical Engineering in 1976 and then received and MSEE from The University of Michigan in 1977 (and joined TI in 1977).  

I also think I greatly oversimplified the contribution of Mark Harward as a co-founder at Syndiant. Mark did much more than just have desigeners, he was the CEO, an investor, and and the company while I “played” with the technology, but I think Mark’s best skill was in hiring great people. Also, Josh Lund, Tupper Patnode, and Craig Waller were co-founders. 

 

ODG R-9: A Peak Behind the Video Curtain

Introduction

With all the hype about Hololens and Magic Leap (ML), Osterhout Design Group (ODG) often gets overlooked. ODG has not spent as much (but still spending 10’s of millions).  ODG has many more years working in field albeit primarily in the military/industrial market.

I don’t know about all the tracking, image generation, wireless, and other features, but ODG should have the best image quality of the three (ODG, Hololens, and ML).  Their image quality was reasonably well demonstrated in a short “through the optics” video ODG made (above and below are a couple crops from frames of that video). While you can only tell so much from a YouTube video (which limits the image quality), they are not afraid to show reasonably small text and large white areas (both of which would show up problems with lesser quality displays).

Update 2016-12-26: A reader “Paul” wrote that he has seen the “cars and ball” demo live. That while the display was locked down, the cubes were movable in the demo. Paul did not know where the computing was done and it could have been done on a separate computer. So it is possible that I got the dividing line between what was “real” and preplanned a bit off. I certainly don’t think that they detected that there was a clear and a black cube, and much of the demo had to have been pre-planned/staged. Certainly it is not a demonstration of what would happen if you were wearing the headset. 

Drawn To Contradictions

As I wrote last time, I’m not a fan of marketing hyperbole and I think calling their 1080p per eye a “4K experience” is at best deliberately confusing. I also had a problem with what Jame Mackie (independent) reporter said about the section of the video starting at 2:29 with the cars and balls in it and linked to here. What I was seeing was not what he was describing.

The sequence starts with a title slide saying, “Shot through ODG smart-glasses with an iPhone 6” which I think is true as far as it what is written. But the commentary by Jame Mackie was inaccurate and misleading:

So now for a real look at how the Holograms appear, as you can see the spatial and geometric tracking is very good. What really strikes me is the accuracy and positioning.  Look how these real life objects {referring to the blocks} sit so effortlessly with the Holograms

I don’t know what ODG told the reporter or if he just made it up, but at best the description is very misleading. I don’t believe there is any tracking being done and all the image rendering  was generated off-line.

What Real Virtual Reality Looks Like

Before getting into detail on the “fake” part of the video, it is instructive to look at a “real” clip. In another part of the video there is a sequence showing replacing the tape in a label maker (starting at 3:25).

In this case, they hand-held the camera rig with the glasses. In the first picture below you can see on the phone that that they are inserting virtual a virtual object, circled in green on the phone, and missing in the “real world”. 

As the handheld rig moves around the virtual elements moves and track with the camera movement reasonably well.  There is every indication that what you are seeing is what they can actually with tracking in an image generation. The virtual elements in three clips from the video are circled in green below.

The virtual elements are in the real demonstration are simple with no lighting effects or reflections off the table. Jame Mackie in the video talks as if he actually tried this demonstrations rather than just describing what he thinks the video shows.

First Clue – Camera Locked Down

The first clue that Cars and Balls video was setup/staged video is that the camera/headset never moves. If the tracking and everything was so good, why not prove it by moving rig with the headset and camera.

Locking the camera down makes it vastly easier to match up pre-recorded/drawn material. As soon as you see the camera locked down with a headset, you should be suspicious of whether some or all of the video has been faked.

Second Clue – Black Cube Highlights Disappeared

Take a look at the black cube below showing the camera rig setup and particularly the two edges of the black cube inside the orange ovals I added. Notice the highlight on the bottom half of each edge and how it looks like the front edge of the clear plastic cube. It looks to me like the black cube was made from a clear cube with the inside colored black. 

Now look at the crop at left from the first frames showing the through the iPhone and optics view. The highlight on the clear cube is still there but strangely the highlights on the black cube have disappeared. Either they switched out the cube or the highlights were taking out in post processing. It is hard to tell because the lighting is so dim.

Third Clue – Looks Too Good – Can’t Be Real Time

2016-12-16 Update: After thinking about it some more, the rending might be in real time. They probably knew there would be a clear and black  box and rendered accordingly with simpler rendering than ray tracing. Unknown is whether the headset or another computer did the rendering. 

According to comments by “Paul” he has seen the the system running. The Headset was locked-down which is a clue that is some “cheating” going on, but he said the blocks were not in a fixed location. 

Looking “too good” is a big giveaway. The cars in the video with all their reflections were clearly using much more complex ray-tracing that was computed off-line. Look at all the reflections of the cars at left. There are both cars reflecting off the table and off the clear cube the flashing light on the police car also acts like a light source in the way it reflect off the cube.

4th Clue: How Did The Headset Know The Cube Was Clear?

One of the first things that I noticed was the clear cube. How are the cameras and sensors going to know it is clear and how it will reflect/refract light? That would be a lot of expensive sensing and processing to figure this out just to deal with this case.

5th Clue: Black Cube Misaligned

On the right is a crop from a frame where the reflection of the car is wrong. From prior frames, I have outlined the black cube with red lines. But the yellow care is visible when it should be hidden by the black cube. There also a reflection in the side of the cube around where the render image is expecting the black cube to be (orange line shows the reflection point).

How It Was Done

2016-12-26 Updates (in blue): Based on the available evidence, the video is uses some amount of misdirection. The video was pre-rendered using a ray tracing computer model with a clear cube and a perfect black shiny cube on a shiny black table being modeled.  They knew that a clear and black cube would be in the scene and locked down the camera. They may have use the sensors to detect where the blocks are to know how to rendering the image. 

They either didn’t have the sensing and tracking ability or the the rendering ability to allow the camera to move.

Likely the grids you see in the video are NOT the headset detecting the scene but exactly the opposite; they are guides to the person setting up the “live” shot as to where to place the real cubes to match where they where in the model. They got the black cube in slightly the wrong place.

The final video was shot through the optics, but the cars and balls where running around the a clear and black cubes assuming they would be there when the video was rendered. No tracking, surface detection, or complex rendering was required, just the ability to playback a pre-recorded video.

Comments

I’m not trying to pick on ODG. Their hype so far less than what I have seen from Hololens and Magic Leap.  I don’t mind companies “simulating” what images will look like provided they indicate they are simulated effects. I certainly understand that through the optics videos and pictures will not look as good as simulated images. But when they jump back and forth between real and simulated effects and other tricks, you start to wonder what is “real.”

ODG R-9 (Horizon): 1080p Per Eye, Yes Really

Lazy Reporting – The Marketing Hyperbole’s Friend

While I have not ODG’s R-9 in person yet, I fully expect that it will look a lot better than Microsoft’s Hololens. I even think it will look better in terms of image quality than what I think ML is working on. But that is not the key point of this article.

But there is also a layer of marketing hyperbole and misreporting going on that I wanted to clear up. I’m just playing referee hear and calling it like a see them.

ODG 4K “Experience” with 2K (1080p) Per Eye


2016-12-28 Update – It appears I was a bit behind on the marketing hype vernacular being used in VR. Most VR displays today, such as Oculus, take a single flat panel and split it between two eyes. So each eye sees less than half (some pixels are cut off) of the pixels. Since bigger is better in marketing, VR makers like to quote the whole flat panel size and not the resolution per eye. 

ODG “marketing problem” is that historically a person working with near eye displays would talk in in terms of “resolution per eye” but this would not be as big by 2X as the flat panel based VR companies market. Rather than being at a marketing hype disadvantage, ODG apparently has adopted the VR flat panel vernacular, however misleading it might be. 


I have not met Jame Mackie nor have I watched a lot of his videos, but he obviously does not understand display technology well and I would take anything he says about video quality with a grain of salt. If should have understood that ODG’s R-9 has is not “4K” as in the title of his YouTube video: ODG 4K Augmented Reality Review, better than HoloLens ?. And specifically he should of asked questions when the ODG employee stated at about 2:22, “it’s two 1080p displays to each eye, so it is offering a 4K experience.

What the ODG marketing person was I think trying to say was that somehow having 1080p (also known as 2K) for each eye was like having a 2 times 2K or “4K equivalent” it is not. In stumbling to try and make the “4K equivalent” statement, the ODG person simply tripped over his own tongue to and said that there were two 1080p devices per eye, when he meant to say there were two 1080p devices in the glasses (one per eye). Unfortunately Jame Mackie didn’t know the difference and did not realize that this would have been impossible in the R-9’s form factor and didn’t follow up with a question. So the  false information got copied into the title of the video and was left as if it was true.

VRMA’s Micah Blumberg Asks The Right Questions and Get The Right Answer – 1080p Per Eye

This can be cleared up in the following video interview with Nima Shams, ODG’s VP of Headworn: “Project Horizon” AR VR Headset by VRMA Virtual Reality Media“. When asked by Micah Blumberg starting at about 3:50 into the video, “So this is the 4K headset” to which Nima Sham responds, “so it is 1080p to each eye” to which Blumberg astutely makes sure to clarify with, “so we’re seeing 1080p right now and not 4K” to which Nima Sham responds, “okay, yeah, you are seeing 2K to each eye independently“.  And they even added an overlay in the video “confirmed 2K per eye.” (see inside the read circle I added).

A Single 1080p OLED Microdisplay Per Eye

Even with “only” 1080p OLED microdisplay per eye with a simple optical path the ODG R-9 should have superior image quality compared to Hololens:

  1. OLEDs should give better contrast than Hololens’ Himax LCOS device
  2. There will be no field sequential color breakup with head or image movment as there can be with Hololens
  3. They have about the same pixels per arc-minute at Hololens but with more pixels they increase FOV from about 37 degrees to about 50 degrees.
  4. Using a simple plate combiner rather than the torturous path of Hololens’ waveguide, I would expect the pixels to be sharper and with little visible chroma aberrations and no “waveguide glow” (out of focus light around bright objects). So even though the angular resolution of the two is roughly the same, I would expect the R-9 to look sharper/higher resolution.

The known downsides compared to Hololens:

  1. The ODG R-9 does not appear to have enough “eye relief” to support wearing glasses.
  2. The device puts a lot of weight on the nose and ears of the user.

I’m not clear about the level of tracking but ODG’s R-9 does not appear to have the number of cameras and sensors that Hololens has for mapping/locking the real world. We will have to wait and see for more testing on this issue. I also don’t have information on how comparable the level of image and other processing is done by the ODG relative to Horizon.

Conclusion

Micah Blumberg showed the difference between just repeating what he is told and knowing enough to ask the right followup question. He knew that ODG had a 4K marketing message was confusing and that what he was being told was at odds with what he was being told so he made sure to clarify it. Unfortunately while James Makie got the “scoop” on the R-9 being the product name for Horizon, he totally misreported the resolution and other things in his report (more on that later).

Lazy and ill informed reporters are the friend and amplifier of marketing hyperbole. It appears that ODG is trying to equate dual 1080p displays per eye with being something like “4K” which is really is not. You need 1080p (also known as 2K) per eye to do stereo 1080p, but that is not the same as “4K” which which is defined as 3840×2060 resolution or 4 times the spatial resolution of 1080p. Beyond this, qualifiers of like “4K “Experience” which has no real meaning are easily dropped and ill informed reporters will report it as “4K” which does have a real meaning.

Also, my point is not meant to pick on ODG, they just happen to be the case at hand. Unfortunately, most of the display market is “liars poker.” Companies are fudging on display specs all the time. I rarely see a projector that meets or exceeds it “spec” lumens. Resolutions are often spec’ed in misleading ways (such as specifying the input rather than the “native” resolution). Contrast is another place were “creative marketing” is heavily used. The problem is that because “everyone is doing it” people feel they have to just to keep up.

The problem for me comes when I have to deal with people that have read false or misleading information. It gets hard to separate truth from marketing exaggeration.

This also goes back to why I didn’t put much stock in the magazine reports about Magic Leap looked. These reports were made by people that were easy to impress and likely not knowledgeable about display devices. They probably could not tell the display resolution by 2X in each direction or would notice even moderately severe image problems. If they were shown a flashy looking demo they would assume it was high resolution.

One More Thing – Misleading/Fake “True Video”

It will take a while to explain (maybe next time), I believe the James Makie video also falsely indicates at 2:29 in the video (the part with the cars and the metal balls on the table), that what is being shown is how the ODG R-9 works.

In fact, while the images of the cars and balls are generated by the R-9, there tracking of the real world and the reflections off the surfaces are a well orchestrated FAKE. Basically they were playing a pre-rendered video though the glasses (so that part is likely real). But clear and black boxes on the table where props there to “sell the viewer” that this was being rendered on the fly.  There also appears to be some post-processing in the video. Most notably, it looks like the black box was modified in post production. There are several clues in the video that will take a while to explain.

To be fair to ODG, the video does not claim to not be fake/processed, but the way it is presented within Jame Makie’s video is extremely misleading to say the least. It could be that the video was taken out of context.

For the record, I do believe the video starting at 4:02 which I have analyze before is a genuine through the optics video and is correctly so identified on the video. I’m not sure about the “tape replacement” video at 3:23, I think it may be genuine or it could be some cleaver orchestrating.

Magic Leap: Focus Planes (Too) Are a Dead End

What Magic Leap Appears to be Doing

For this article I would like to dive down on the most likely display and optics Magic Leap (ML) is developing for their their Product Equivalent (PEQ). The PEQ was discussed in the “The Information” story “The Reality Behind Magic Leap.” As I explained in my  November 20, 2016 article Separating Magic and Reality (before the Dec 8th “The Information” story) the ML patent application US 2016/0327789 best fits the available evidence and if anything the “The Information” article reinforce that conclusion. Recapping the evidence:

  1. ML uses a “spatial light modulator” as stated in “The Information”
  2. Most likely an LCOS spatial light modulator and the Oct. 27th 2017 Inside Business citing “KGI Securities analyst Ming-Chi Kuo, who has a reputation for being tapped into the Asian consumer electronics supply chain” claims ML is using a Himax LCOS device.
  3. Focus planes to support vergence/accommodation per many ML presentations and their patent applications
  4. Uses waveguides which fit the description and pictures of what ML calls a “Photonics Chip”
  5. Does not have a separate focus mechanism as reported in the “The Information” article.
  6. Could fit the form factor as suggested in “The Information”
  7. Its the only patent that shows serious optical design that also uses what could be considered a “Photonics chip.”

I can’t say with certainty that the optical path is that of application 2016/0327789. It is just the only optical path in the ML patent applications that fits all the available evidence and and has a chance of working.

Field of View (FOV)

Rony Abovitz, ML CEO, is claiming a larger a larger FOV.  I would think ML would not want to be have lower angular resolution than Hololens. Keeping the same 1.7 arc minutes per pixel angular resolution as Hololens and ODG’s Horizon, this would give a horizontal FOV of about 54.4 degrees.

Note, there are rumors that Hololens is going to be moving to a 1080p device next year so ML may still not have an advantage by the time they actually have a product. There is a chance that ML will just use a 720p device, at least at first, and accept lower angular resolution of say 2.5 or greater to get into the 54+ FOV range. Supporting a larger FOV is not small trick with waveguides and is  one thing that ML might have over Hololoens; but then again Hololens is not standing still.

Sequential Focus Planes Domino Effect

The support of vergence/accommodation appears to be a paramount issue with ML. Light fields are woefully impractical for any reasonable resolution, so ML in their patent application and some of their demo videos show the concept of “focus planes.” But for every focus plane an image has to be generated and displayed.

The cost of having more than one display per eye including the optics to combine the multiple displays would be both very costly and physically large. So the only rational way ML could support focus planes is to use a single display device and sequentially display the focus planes. But as I will outline below, using sequential focus planes to address vergence/accommodation, comes at the cost of hurting other visual comfort issues.

Expect Field Sequential Color Breakup If Magic Leap Supports “Focus Planes”

Both high resolution LCOS and DLP displays use “field sequential color” where they have a single set of mirrors that display a single color plane at a time. To get the colors to fuse together in the eye they repeat the same colors multiple times per frame of an image. Where I have serious problems with ML using Himax LCOS is that instead of repeating colors to reduce the color breakup, they will be instead be showing different images to support Sequential Focus Planes. Even if they have just two focus planes as suggested in “The Information,” it means they will reduce the rate repeating of colors to help them fuse in the eye is cut in half.

The Hololens which also uses a field sequential color LCOS one can already detect breakup. Cutting the color update rate by 2 or more will make this problem significantly worse.

Another interesting factor is that field sequential color breakup tends to be more noticeable by people’s peripheral vision which is more motion/change sensitive. This means the problem will tend to get worse as the FOV increases.

I have worked many years with field sequential display devices, specifically LCOS. Based on this experience I expect that the human vision system  will do a poor job of “fusing” the colors at such slow color field update rates and I would expect people will see a lot of field sequential color breakup particularly when objects move.

In short, I expect a lot of color breakup to be noticeable if ML support focus planes with a field sequential color device (LCOS or DLP).

Focus Planes Hurt Latency/Lag and Will Cause Double Images

An important factor in human comfort is the latency/lag between any head movement and the display reacting can cause user discomfort. A web search will turn up thousands of references about this problem.

To support focus planes ML must use a display fast enough to support at least 120 frame per second. But to support just two focus planes it will take them 1/60th of a second to sequentially display both focus planes. Thus they have increase the total latency/lag from the time they sense movement until the display is updated by ~8.333 milliseconds and this is on top of any other processing latency. So really focus planes is trading off one discomfort issue, vergence/accommodation, for another, latency/lag.

Another issue which concerns me is how well sequential focus planes are doing to fuse in the eye. With fast movement the eye/brain visual system is takes its own asynchronous “snapshots” and tries to assemble the information and line it up. But as with field sequential color, it can put together time sequential information wrong, particularly if some objects in the image move and others don’t. The result will be double images, getting double images with sequential focus planes would be unavoidable with fast movement either in the virtual world or when a person moves their eyes. These problems will be compounded by color field sequential breakup.

Focus Planes Are a Dead End – Might Magic Leap Have Given Up On Them?

I don’t know all the behind the scenes issues with what ML told investors and maybe ML has been hemmed in by their own words and demos to investors. But as an engineer with most of my 37 years in the industry working with image generation and display, it looks to me that focus planes causes bigger problems than it solves.

What gets me is that they should have figured out that focus planes were hopeless in the first few months (much less if someone that knew what they were doing was there). Maybe they were ego driven and/or they built to much around the impression they made with their “Beast” demo system (big system using DLPs). Then maybe they hand waved away the problems sequential focus planes cause thinking they could fix them somehow or hoped that people won’t notice the problems. It would certainly not be the first time that a company committed to a direction and then felt that is had gone to far to change course. Then there is always the hope that “dumb consumers” won’t see the problems (in this case I think they will).

It is clear to me that like Fiber Scan Displays (FSD), focus planes are a dead end, period, full-stop. Vergence/accommodation is a real issue but only for objects that get reasonably close to the users. I think a much more rational way to address the issue is to use sensors to track the eyes/pupils and adjust the image accordingly as the eye’s focus changes relatively slowly it should be possible to keep up. In short, move the problem from the physical display and optics domain (that will remain costly and problematical), to the sensor and processing domain (that will more rapidly come down in cost).

If I’m at Hololens, ODG, or any other company working on an AR/MR systems and accept that vergence/accommodation is a problem needs to be to solve, I’m going to solve it with eye/pupil sensing and processing, not by screwing up everything else by doing it with optics and displays. ML’s competitors have had enough warning to already be well into developing solutions if they weren’t prior to ML making such a big deal about the already well known issue.

The question I’m left is if and when did Magic Leap figured this out and were they too committed by ego or what they told investors to focus planes to change at that point? I have not found evidence so far in their patent applications that they tried to changed course, but these patent applications will be about 18 months or more behind what they decided to do. But if they don’t use focus planes, they would have to admit that they are much closer to Hololens and other competitors than they would like the market to think.

Magic Leap: “The Information” Article

The Information: The Reality Behind Magic Leap

the-information-magic-leap-dec-8-2016-coverThe online news magazine “The Information” released the article “The Reality Behind Magic Leap” on Dec. 8th, 2016, by Reed Albergotti and in the story gave a link to this blog. So you may be a new reader.  The article appears to be well researched and I understand that “The Information” has a reputation as a reliable news source. The article also dovetails nicely on the business side with what I have been discussing with this blog on the technical side. The magazine is a paid publication but there is a summary on The Verge along with their added commentary and a lot of the text from the article has shown up in discussion forums about Magic Leap (ML).

For this blog post, I am going to try put 2+2 together between what I have figured out on the technical side and what Mr. Albergotti reported on the business side. Note, I have not seen what he as seen so I am reading between the lines somewhat but hopefully it will give a more complete picture.

The Magic Leap Prototypes

The article states “Magic Leap CEO Rony Abovitz acknowledged that the prototypes used different technology.” This blog has identified that the early prototypes as:

  1. ml-495-applicationA DLP based prototype that uses a variable focus lens to produce “focus planes” by generating different images for different distances and changing the focus between images and supported maybe 3 to 6 focus planes. This is probably their earliest one and is what the article calls “The Beast” and described as the “size of a refrigerator.”
  2. One or more OLED base variations once again using an electrically controlled focus element where ML made a smaller helmet version. The article discussed only one version, dubbed “WD3” but I suspect that they had variations of this one with different capabilities (as in maybe a WD1, WD2, WD3 and maybe more). I believe based on the video evidence a version that could only change focus was used for their Oct. 14, 2015 through the technology” video.  Their later “A New Morning” and “Lost Droids” videos appear to use an Mico-OLED based optics that supported at least two simultaneous focus planes by running the OLED at 120hz to generate two 60hz sequential “focus plane” images and changing the focus be each one.
  3. ml-slm-beam-splitter-lcos-type-optics-colorThe LCOS version that is using their “Photonic Chip” and supports about 2 focus planes with no moving focusing optics (according to the article); what the article dubbed the “PEQ” prototype.

If you want to get more into the gory technical details on how the above work, I would suggest one of my earlier articles titled “Magic Leap – Separating Magic and Reality“. And if you really want to get dirty, read the ML patent applications they reference but be prepared for a long read as they they cover a lot of totally different concepts.

As this blog has been reporting (and for which I have gotten criticism on some of the on-line discussion forms), the must discussed “fiber scanning display” (FSD) has not been perfected and with it any chance of making the “light field display” ML has talked so much about. Quoting the article,”Magic Leap relegated the fiber scanning display to a long-term research project in hopes that it might one day work, and significantly pared back on its light field display idea.

Possible Scenario – A Little Story

Based on my startup and big company experiences, I think I understand roughly how it went down. Please take the rest of this section as reasonable speculation and reading between the lines of known information. So I am going to play Columbo (old TV series reference) below to give my theory of how it went down.

Startups have sometimes been described as “Jumping out of a plane and sewing a parachute on the way down.” This appears to be the case with Magic Leap. They had a rough idea of what they wanted to do and were able to build an impressive demo system and with some good hand waving convince investors they could reduce it to a consumer headset.

They found Brian Schowengerdt, co-founder and Chief Scientist, who worked on the fiber scanning display (FSD) technology and the issue of vergence and accomodation at the University of Washington to join. Mr. Schowengerdt is clearly a smart person that added a lot of credibility to Rony Abovitz’s dreams. The problem with “university types” is that they often don’t appreciate what it takes to go from R&D to a real high volume product.

The “new optical people” built “The Beast” prototype using DLP’s and electrical controlled focusing lenses to support multiple focus plane, to address the vergence and accommodation issue. They then used the “Jedi Hand Wave Mind Trick” (ordinary hand waving may not be enough) to show the DLP engine, the crude low resolution FSD display from the U of W, some non-functional waveguides, and a mock-up of how wonderful it would be someday with a simple application of money and people (if you can dream it you can build it, right?).

This got them their “big fish,” Google who was attuned to the future of near eye displays with their investment in Google Glass and all the big noise with Oculus Rift. There is phenomenal FoMO (Fear of Missing Out) going on with AR/VR/MR  The fact they got a lot of money from a big name company became it own publicity and fund raising engine. ML then got showered with money and that they hoped could cover the bet. Have Google invest publicly also became its own shield against any question of whether it would work.

All the money gave them a lot of altitude to try and build the proverbial parachute on the way down. But sometimes the problem is harder than all the smart people and money can solve. As I have pointed out on this blog, making the fiber scan display work at high resolution is no small task if not impossible. They came to realize this at some point, probably early on, that FSD were not going to happen in a meaningful time frame.

So “plan B” became to use an existing working display technology to give a similar visual effect, even if much reduced in resolution. The beast is way to big and expensive to cost reduce and then need to have more demo systems that are easier to make.

So then they make the WDx based on OLEDs. But there is fatal flaw with using OLEDs (and it tripped me up at first when looking at the videos). While OLED make the design much easier and smaller the don’t work due to the nature of the they put out with the wonderfully flat waveguides (what ML calls their “Photonics Chip”) that ML has convince investors are part of their secret sauce.

So if they couldn’t use the Photonics Chip with OLEDs and the FSD is a no-go, what do you tell investors, both of your secret sauces are a bust? So in parallel they are working on plan “C” which is to use LCOS panels with LED light sources that will work with some type of waveguide which they will dub the “Photonics Chip”.

But then there is a fly in the ointment. Microsoft starts going public with their Hololens system making Magic Leap look like they are way behind the giant Microsoft that can spend even more money than ML can raise. They need to show something to stay relevant. They start with totally fake videos and get called on the carpet for being obviously fake. So they need a “Magic Leap Technology” (but not the optics they are actually planning on using) demo.

The “Beast System” with it DLP’s and field sequential color will not video well. The camera will reveal to any knowledgeable expert what they are using. So for the video they press into service the WDx OLED systems that will video better. By cleaver editing and only showing short clips, they can demonstrate some focus effects while not showing the limitations of the WDx prototypes. These videos then make ML seem more “real” and keep people from asking too many embarrassing questions.

A problem jhere is that LCOS is much slower than DLP’s and thus they may only be able to support about 2 focus planes. I also believe from 16 years working with LCOS that this likely to look like crap to the eye due to color field breakup; but reapplying the Jedi Mind Trick, maybe two focus planes will work and people won’t notice the color field breakup. And thus you have the PEQ which still does not work well or would be demoing with it rather than the helmet sized WD3.

I suspect that Reed Albergotti from “The Information” had gotten the drop on ML by doing some good investigative journalism work. He told them he was going to run with the story and ML decided to try see if they could do damage control and invited him in. But apparently he was prepared and still saw the holes in their story.

Epilogue: It sounds like Mr. Schowengerdt has been put off to the side having served is usefulness in raising money. They used the money to hire other optical experts who knew how to design the optics they would actually be using. He may be still playing around the FSD to keep the dream alive of a super high resolution display someday and maybe the the next to impossible high resolution light fields (I would suggest reading “The Horse Will Talk Fable” to gain insight into why they would keep doing this as an “R&D” program).

I’m probably a little off in the details, but it probably went down something like the above. If not, hopefully you found it an amusing story. BTW, if you want to make a book and or movie out of this original story please consider it my copyrighted work (c) 2016 (my father was and two brothers are Patent Lawyers and I learned about copyright as a small child at my fathers knee).

Lessons Learned

In my experience startups that succeed in building their product have more than a vague idea of what they want to do and HOW they are going to do it. They realize that money and smart people can’t cure all ills. Most importantly they understand where they have risk and then only have at most A SINGLE serious risk. They then focus on making sure they covering that risk. In the case of Magic Leap, they had multiple major risks in many different areas. You can’t focus on the key risk because there so many and it is a prescription for product failure no matter how much money is applied.

Its even possible the “smart money” that invested realized that ML realized that they were unlikely to totally succeed but thought with money and smart people they might spin out some valuable technology and/or patents. The “equation works” if they multiply a hoped by $100B/year market by even a small chance of success. If a big name places what is for them a small bet, it is surprising how much money will follow along assuming the big name investor had done all the hard work of due diligence.

Even if they get paste the basic technology risk get the PEQ running. We they will then have the problem of building a high volume product, worse yet they are building their own factory. And then we have the 90/90 rule which states, “it takes 90% of the effort to get 90% of the way there and then another 90% to solve the last 10%.” When you have a fully working prototype that behaves well (which by the reports in ML has NOT achieved yet) you have just made it to the starting line; then you have to make it manufacturable at a reasonable cost and yield. Other have said it is really 90/90/90 where there is a third 90%. This is where many a Kickstarter company has spun their wheels.

Magic Leap & Hololens: Waveguide Ego Trip?

ml-and-hololens-combiner-cropThe Dark Side of Waveguides

Flat and thin waveguides are certainly impressive optical devices. It is almost magical how you can put light into what looks a lot like thin plates of glass and an small image will go on one side and then with total internal reflection (TIR) inside the glass, the image comes out in a different place. They are coveted by R&D people for their scientific sophistication and loved by Industrial Designers because they look so much like ordinary glass.

But there is a “dark side” to waveguides, at least every one that I have seen. To made them work, the light follows a torturous path and often has to be bent at about 45 degrees to couple into the waveguide and then by roughly 45 degrees to couple out in addition to rattling of the two surfaces while it TIRs. The image is just never the same quality when it goes through all this torture. Some of the light does not make all the turns and bends correctly and it come out in the wrong places which degrade the image quality. A major effect I have seen in every diffractive/holographic waveguid  is I have come to call “waveguide glow.”

Part of the problem is that when you bend light either by refraction or using diffraction or holograms, the various colors of light bend slightly differently based on wavelength. The diffraction/holograms are tuned for each color but invariably they have some effect on the other color; this is particularly problem is if the colors don’t have a narrow spectrum that is exactly match by the waveguide. Even microscopic defects cause some light to follow the wrong path and invariably a grating/hologram meant to bend say green, will also affect the direction of say blue. Worse yet, some of the  light gets scattered, and causes the waveguide glow.

hololens-through-the-lens-waveguide-glowTo the right is a still frame from a “Through the lens” video” taken through the a Hololens headset. Note, this is actually through the optics and NOT the video feed that Microsoft and most other people show. What you should notice is a violet colored “glow” beneath the white circle. There is usually also a tendency to have a glow or halo around any high contrast object/text, but it is most noticeable when there is a large bright area.

For these waveguides to work at all, they require very high quality manufacturing which tends to make them expensive. I have heard several reports that Hololens has very low yields of their waveguide.

I haven’t, nor have most people that have visited Magic Leap (ML), seen though ML’s waveguide. What  ML leap shows most if not all their visitors are prototype systems that use non-waveguide optics has I discussed last time. Maybe ML has solved all the problems with waveguides, if they have, they will be the first.

I have nothing personally against waveguides. They are marvels of optical science and require very intelligent people to make them and very high precision manufacturing to make. It is just that they always seem to hurt image quality and they tend to be expensive.

Hololens – How Did Waveguides Reduce the Size?

Microsoft acquired their waveguide technology from Nokia. It looks almost like they found this great bit of technology that Nokia had developed and decided to build a product around it. hololensBut then when you look at Hololens (left) there is this the shield to protect the lenses (often tinted but I picked a clear shield so you could see the waveguides). On top of this there is all the other electronic and frame to mount it on the user’s head.

The space savings from the using waveguides over much simpler flat combiner  is a drop in the bucket.

ODG Same Basic Design for LCOS and OLED

I’m picking Osterhout Design Group’s for comparison below because because they demonstrate a simpler, more flexible, and better image quality alternative to using a waveguide. I think it makes a point. Most probably have not heard of them, but I have know of them for about 8 or 9 years (I have no relationship with them at this time). They have done mostly military headsets in the past and burst onto the public scene when Microsoft paid them about $150 million dollars for a license to their I.P. Beyond this they just raised another $58 million from V.C.’s. Still this is chump change compared to what Hololens and Magic Leap are spending.

Below is the ODG R7 LCOS based glasses (with the one of the protective covers removed). Note, the very simple flat combiner. It is extremely low tech and much lower cost compared to the Hololens waveguide. To be fair, the R7 does not have as much in the way of sensors and processing as the as Hololens.

odg-r-with-a-cover-removed

The point here is that by the time you put the shield on the Hololens what difference does having a flat waveguide make to the overall size? Worse yet, the image quality from the simple combiner is much better.

Next, below is ODG’s next generation Horizon glasses that use a 1080p Micro-OLED display. It appears to have somewhat larger combiner (I can’t tell if it is flat or slightly curved from the available pictures of it) to support the wider FOV and a larger outer cover, but pretty much the same design. The remarkable thing is that they can use the a similar optical design with the OLEDs and the whole thing is about the same size where as the Hololens waveguide won’t work at all with OLEDs due broad bandwidth colors OLEDs generate.

odg-horizons-50d-fov

ODG put up a short video clip through their optics of the Micro-OLED based Horizon (they don’t come out and say that it is, but the frame is from the Horizon and the image motion artifacts are from an OLED). The image quality appears to be (you can’t be too quantitative from a YouTube video) much better than anything I have seen from waveguide optics. There is not of the “waveguide glow”. odg-oled-through-the-optics-002

They even were willing to show text image with both clear and white backgrounds that looks reasonably good (see below). It looks more like a monitor image except for the fact that is translucent. This is the hard content display because you know what it is supposed to look like so you know when something is wrong. Also, that large white area would glow like mad on any waveguide optics I have seen. odg-oled-text-screen-002

The clear text on white background is a little hard to read at small size because it is translucent, but that is a fundamental issue will all  see-though displays. The “black” is what ever is in the background and the “white” is the combination of the light from the image and the real world background.  See through displays are never going as good as an opaque displays in this regards.

Hololens and Magic Leap – Cart Before the Horse

It looks to me like Hololens and Magic Leap both started with a waveguide display as a given and then built everything else around it. They overlooked that they were building a system. Additionally, they needed get it in many developers hands as soon as possible to work out the myriad of other sensor, software, and human factors issues. The waveguide became a bottleneck, and from what I can see from Hololens was an unnecessary burden. As my fellow TI Fellow Gene Frantz and I used to say when we where on TI’s patent committeed, “it is often the great new invention that causes the product to fail.”

I (and few/nobody outside of Magic Leap) has seen an image through ML’s production combiner, maybe they will be the first to make one that looks as good as simpler combiner solution (I tend to doubt it, but it not impossible). But what has leaked out is that they have had problems getting systems to their own internal developers. According the Business Insider’s Oct. 24th article (with my added highlighting):

“Court filings reveal new secrets about the company, including a west coast software team in disarray, insufficient hardware for testing, and a secret skunkworks team devoted to getting patents and designing new prototypes — before its first product has even hit the market.”

From what I can tell of what Magic Leap is trying to do, namely focus planes to support vergence/accommodation, they could have achieved this faster with more conventional optics. It might not have been as sleek or “magical” as the final product, but it would have done the job, shown the advantage (assuming it is compelling) and got their internal developers up and running sooner.

It is even more obvious for Hololens. Using a simple combiner would have added trivially to the the design size while reducing the cost and getting the the SDK’s in more developer’s hands sooner.

Summary

It looks to me that both Hololens and likely Magic Leap put too much emphasis on the using waveguides which had a domino effect in other decisions rather than making a holistic system decision. The way I see it:

  1. The waveguide did not dramatically make Hololens smaller (the case is still out for Magic Leap – maybe they will pull a rabbit out of the hat). Look at ODG’s designs, they are every bit as small.
  2. The image quality is worse with waveguides than simpler combiner designs.
  3. Using waveguides boxed them in to using only display devices that were compatible with their waveguides. Most notably they can’t use OLED or other display technology that emit broader spectrum light.
  4. Even if it was smaller, it is more important to get more SDKs in developers (internal and/or external hand) sooner rather than later.

Hololens and Magic Leap appear to be banking on getting waveguides into volume production in order to solve all the image quality and cost problems with them. But it will depend on a lot of factors, some of which are not in their control, namely, how hard it is to make them well and at a price that people can afford. Even if they solve all the issues with waveguides, it is only a small piece of their puzzle.

Right now ODG seems to be taking more the of the original Apple/Wozniak approach; they are finding elegance in a simpler design. I still have issues with what they are doing, but in the area of combining the light and image quality, they seem to be way ahead.

Magic Leap: When Reality Hits the Fan

Largely A Summary With Some New Information

ml-slm-beam-splitter-lcos-type-optics-colorI have covered a lot of material and even then only glossed at the surface of what I have learned about Magic Leap (ML). By combining the information available (patent applications, articles, and my sources), I have a fairly accurate picture of what Magic Leap is actually doing based on feedback I have received from multiple sources.

This blog has covered a lot of different topics and some conclusions have changed slightly as I discovered more information and with feedback from some of my sources. Additionally, many people just want “the answer.” So I thought it would be helpful to summarize some of the key results including some more up to date information.

What Magic Leap Is Not Doing In The Product

Between what I have learned and feedback from sources I can say conclusively that ML is not doing the following:

  1. Light Fields – These would requires a ridiculously large and expensive display system for even moderate resolution.
  2. Fiber Scan Displays – They have demonstrated low resolution versions of these and may have used them to convince investors that they had a way to break through the limitations of pixel size of Spatial Light Modulators (SLM) like LCOS, DLP, and OLEDs. Its not clear how much they improved the technology over what the University of Washington had done, but they have given up on these being competitive in resolution and cost with SLMs anytime soon. It appears to have been channeled into being a long term R&D effort and to keep the dream alive with investors.
  3. Laser Beam Scanning (LBS) by Microvision or anyone else – I only put this on the list because of an incredibly ill-informed new release by Technavio stating “Magic Leap is yet to release its product, and the product is likely to adopt MicroVision’s VRD technology.” Based on this, I would give the entire report they are marketing zero credibility; I think they are basing their reports on reading fan-person blogs about Microvision.
  4. OLED Microdisplays – They were using these in their demos and likely in the video they made, but OLED are incompatible optically with there use of a diffractive waveguide (= ML’s Photonic Chip).
Prototypes that Magic Leap Has Shown
  1. FSD – Very low resolution/crude green only fiber scanned display. This is what Rachel Metz described (with my emphasis added) in her MIT Technology Review March/April 2015 article, “It includes a projector, built into a black wire, that’s smaller than a grain of rice and channels light toward a single see-through lens. Peering through the lens, I spy a crude green version of the same four-armed monster that earlier seemed to stomp around on my palm.
  2. ml-495-applicationTI DLP with a conventional combiner and  a “variable focus element” (VFE). They use the DLP to generate a series of focus planes time sequentially and change the VFE between the sequential focus planes. Based on what I have heard, this is their most impressive demo visually and they have been using this for over a year, but the system is huge.
  3. OLED with a conventional combiner (not a waveguide/”Photonics Chip”). This is likely the version they used to shoot their “Through Magic Leap Technology” videos that I analyzed in my Nov. 9th, 2016 blog post. In that article I though that Micro-OLED might be used in the final product, but I have revised this opinion. OLEDs output very wide bandwidth light that is incompatible with waveguides, so it would be incompatible with working with Photonics Chip ML makes such a big deal about.

What is curious is that none of these prototypes, with the possible exception of #1, the single color low resolution FSD, are using a “waveguide.” Waveguides are largely incompatible with OLEDs and having a variable focus element is also problematical.  Also none of these are using LCOS, the most likely technology in the final product.

What Magic Leap Is Trying to Do In Their First “Product”

I’m going to piece together below what I believe based on the information available from both public information and some private conversations (but none of it is based on NDA’ed information as far as I am aware).

  1. ml-slm-beam-splitter-lcos-type-optics-colorLCOS Microdisplay – All the evidence including Business Insider’s October 27, 2016 points to ML using LCOS. They need a technology that will work well with waveguides using narrow band (likely LED) light sources that they can make as bright as necessary and control the angle of the light illumination. LCOS is less expensive, more optically compact, and requires less power than DLP for near eye systems. All these reason are same as why Hololens is using LCOS. Note, I’m not 100% sure on them using LCOS, but it by far the most likely technology they will be using. They could also be using DLP but I would put that at less than a 10% chance. I’m now ruling out Micro-OLED because it would not work in a waveguide.
  2. Two (2) sequential focus planes are supported – The LCOS microdisplay is likely only able to support about 120 full color frames per second which is only enough to support 2 sequential focus planes per 1/60th of a second of a moving image. Supporting more planes at a slower rate would result in serious image breakup when things move. The other big issue is the amount of processing required. Having even two focus planes greatly increase the computation that have to be done. To make it work correctly, they will need to track the person’s pupils and factor that into their processing and deal with things like occlusion. Also with the limited number of focus planes they will have to figure out how to “fake” or deal with a wider range of focus.
  3. Variable Focus – What I don’t know is how they are supporting the change in focus between the sequential focus planes. They could be using some form of electrically alterable lens but it is problematical to have non-collimated light entering a waveguide. It would therefore seem more consistent for them to be using the technique shown in their patent application US 2016/0327789 that I discussed before.
  4. Photmagic-leap-combiner-croponics Chip (= Diffractive Waveguide) – ML has made a big deal about their Photonic’s Chip, what everyone else would call a “waveguide.” The Photonics Chip likely works similar to the one Hololens uses (for more information on waveguides, see my Oct 27th, 2016 post). The reports are that Hololens has suffered low yields with their Waveguides and Magic Leaps will have more to do optically to support focus planes.
Comments

Overall, I think it it is very clear that what they will actually make is only a fraction of he vision they have portrayed to the press. They may have wanted to do 50 megapixel equivalent foveated displays, use FSD as their display device, have 6 focus planes, or even (from Fortune July 12, 2016) ““light-field” technology essentially mimics the brain’s visual-perception mechanisms to create objects and even people who look and behave just the way they would in the real world, and interact with that world seamlessly.” But then, they have to build something that actually works and that people can afford to buy. Reality then hits the fan

 

Magic Leap – Fiber Scanning Display Follow UP

Some Newer Information On Fiber Scanning

Through some discussions and further searching I found some more information about Fiber Scanning Displays (FSD) that I wanted to share. If anything, this material further supports the contention that Magic Leap (ML) is not going to have a high resolution FSD anytime soon.

Most of the images available is about fiber scanning for use as a endoscope camera and not as a display device. The images are of things like body parts they really don’t show resolution or the amount of distortion in the image. Furthermore most of the images are from 2008 or older which gives quite a bit of time for improvement. I have found some information that was generated in the 2014 to 2015 time frame that I would like to share.

Ivan Yeoh’s 2015 PhD dissertation

2015-yeoh-laser-projection

In terms of more recent fiber scanning technology, Ivan Yeoh’s name seems to be a common link. Show at left is a laser projected image and the source test pattern from Ivan Yeoh’s 2015 PhD dissertation “Online Self-Calibrating Precision Scanning Fiber Technology with Piezoelectric Self-Sensing“at the University of Washington. It is the best quality image of a test pattern or known image that I have found of a FSD anywhere. The dissertation is about how to use feedback to control the piezoelectric drive of the fiber. While his paper is about the endoscope calibration, he nicely included this laser projected image.

The drive resulted in 180 spirals which would nominally be 360 pixels across at the equator of the image with a 50Hz frame rate. But based on the resolution chart, the effective resolution is about 1/8th of that or only ~40 pixels, but about half of this “loss” is due to resampling a rectilinear image onto the spiral. You should also note that there is considerably more distortion in the center of the image where the fiber will be moving more slowly.

2015-yeoh-endoscope-manual-calibrationYeoh also included some good images at right showing how had previously used a calibration setup to manually calibrate the endoscope before use as it would go out of calibration with various factors including temperature. These are camera images and based on the test charts they are able to resolve about 130 pixels across which is pretty close to the Nyquist sampling rate from a 360 samples across spiral. As expected the center of the image where the fiber is moving the slowest is the most distorted.

While a 360 pixel camera is still very low resolution by today’s standards, it is still 4 to 8 times better than the resolution of the laser projected image. Unfortunately Yeoh was concerned with distortion and does not really address resolution issues in his dissertation. My resolution comments are based on measurements I could make from the images he published and copied above.

Washington Patent Application Filed in 2014

uow-2016-fsd-applicationYeoh is also the lead inventor on the University of Washington patent application US 2016/0324403 filed in 2014 and published in June 2016. At left is Fig. 26 from that application. It is supposed to be of a checkerboard pattern which you may be able to make out. The figure is described as using a “spiral in and spiral out” process where the rather than having a retrace time, they just reverse the process. This applications appears to be related to Yeoh’s dissertation work. Yeoh is shown as living in Fort Lauderdale, FL on the application, near Magic Leap headquarters.   Yeoh is also listed as an inventor on the Magic Leap application US 2016/0328884 “VIRTUAL/AUGMENTED REALITY SYSTEM HAVING DYNAMIC REGION RESOLUTION” that I discuss in my last article. It would appear that Yeoh is or has worked for Magic Leap.

2008 YouTube Video

ideal-versus-actually-spiral-scan

Additionally, I would like to include some images from a 2008 YouTube Video that kmanmx from the Reddit Magic Leap subreddit alerted me to. White this is old, it has a nice picture of the fiber scanning process both as a whole and with close-up image near the start of the spiral process.

For reference on the closeup image I have added the size of a “pixel” for a 250 spiral / 500 pixel image (red square) and what a 1080p pixel (green square) would be if you cropped the circle to a 16:9 aspect ratio. As you hopefully can see the spacing and jitter variations-error in the scan process are several 1080p pixels in size. While this information is from 2008, the more recent evidence above does not show a tremendous improvement in resolution.

Other Issues

So far I have mostly concentrated on the issue of resolution, but there are other serious issues that have to be overcome. What is interesting in the Magic Leap and University of Washington patent literature is the lack of patent activity to address the other issues associated with generating a fiber scanned image. If Magic Leap were serious and had solved these issues with FSD, one would expect to see patent activity in making FSD work at high resolution.

One major issue that may not be apparent to the casual observer is the the controlling/driving the lasers over an extremely large dynamic range. In addition to support the typical 256 (8-bits) per color and supporting overall brightness adjustment based on the ambient light, the speed of the scan varies by a large amount an they must compensate for this or end up with a very bright center where the scan is moving more slowly. When you combine it all together they would seem to need to control the lasers over a greater than 2000:1 dynamic range from a dim pixel at the center to a brightest pixel at the periphery.

Conclusion

Looking at all the evidence there is just nothing there to convince me that Magic Leap is anywhere close to having perfected a FSD to the point that it could be competitive with a conventional display device like LCOS, DLP or Micro-OLED, not less the 50 megapixel resolutions they talk about. Overall, there is reasons to doubt that a electromechanical scan process is going to in the long run compete with an all electronic method.

It very well could be that Magic Leap had hoped that FSD would work and/or it was just a good way to convince investors that they had a technology that would lead to super high resolution in the future. But there is zero evidence that have seriously improved on what the University of Washington has done. They may still be pursuing it as an R&D effort but there is no reason to believe that they will have it in a product anytime soon.

All roads point to ML using either LCOS (per Business Insider of October 2016) or a DLP based what I have heard is in some prototypes. This would mean they will likely have either 720p or 1080p resolution display, or the same as others such as Hololens (which will likely have a 1080p version soon).

The whole FSD is about trying to break through the physical pixel barrier of conventional technologies.  There are various physics (diffraction is becoming a serious issue) and material issues that will likely make it tough to make physical pixels much smaller than 3 micron.

Even if there was a display resolution breakthrough (which I doubt based on the evidence), there are issues as to whether this resolution could make it through the optics. As the resolution improves the optics have to also improve or else they will limit the resolution. This is a factor that particularly concerns me with the waveguide technologies I have seen to date that appear to be at the heart of Magic Leap optics.