Gixel comes out of stealth with a new type of AR optical engine

Yesterday, German startup Gixel came out of stealth mode to announce it is working on a new type of optical engine for AR glasses and smartglasses. It also announced a €5M funding round led by several business angels, including the Oculus co-founder Brendan Iribe. Ah, and I also had a secret meeting with them at AWE. Discover all of this, with some information EXCLUSIVE to this blog, by reading this article!

What is Gixel?

Let’s start from the basics: Gixel is a startup based in Germany that is working on a new optical engine for smartglasses and AR glasses. It’s the third time I’ve repeated this sentence, so I guess this is already overly clear to you. You may be aware of other AR optical engines, like waveguides (used e.g. in HoloLens), birdbath (e.g. XREAL), or pinhole (e.g. LetinAR). Gixel is using another approach, which is based on micromirrors. And since it is a new, intriguing mode, it has just gained the trust of some relevant investors.

How does the Gixel optical engine work?

The Gixel optical engine (which may be used in smartglasses and AR glasses, never forget about it :P) works as shown in this picture:

Before describing the inner workings, let’s focus for one moment on the lenses in the Gixel system, because they are not the standard glass/plastic lenses of AR glasses, but they are definitely special. These lenses contain some micromirrors. These micromirrors, thanks to some optoelectrical magic, can change their optical properties, so, for instance, they can be commanded to change the direction they reflect the light to. Inside the lenses, there is some liquid, which has the same refraction index as the elements that mount and move these mirrors, which means that, optically speaking, these control elements do not alter how the light passes by compared to the rest of the lens. The result is a transparent lens with some quasi-transparent micromirrors that can reflect light rays as we wish.

Now that we’ve seen how the lenses are, let’s see the intended behavior of the whole optical system. There is a tiny microOLED projector that projects the image of the virtual elements onto the lenses of the glasses. Remember that on the lenses there are the micromirrors, whose purpose is exactly to reflect these light rays emitted by the projector. On the glasses, there is also an eye-tracking system, able to always detect where your pupil is. The control system of the glasses takes the input of the eye tracking and commands the micromirrors to rotate so as to make sure that the light rays from the projector are reflected into the eyes. So we have a transparent lens that makes you see the real world, and a system of projectors and micromirrors that cast a virtual image into your eyes: the result is that you see augmented reality.

This explains the overall workings. Unluckily, at this stage of the project, the company has not unveiled more details about how its system works, but probably more information is coming in the future.

What are the advantages of this approach?

According to the company, “Gixel’s approach enables optical see-through displays with smartphone-level quality, stellar transparency when the display is off, and extremely energy-efficient, low-weight, low-heat operation. Designed for industrial-scale manufacturing, it supports curved lenses for sleek form factors, variable focal planes for correct depth placement, and a scalable field of view, from small zones to the entire lens. Its scalable design gives OEMs freedom to choose the field of view and place displays anywhere on the lens.”

Long story short, the Gixel team is convinced that its technology ensures more power-efficient AR glasses with a much larger FOV than the current technology. The other interesting advantage is that, depending on how many micromirrors you add to the lenses, you can have different configurations with different FOVs, so with this optical engine, it is possible to make many different products with different characteristics.

And the lenses used by these glasses can be very transparent, and not feel darkened like it happened, for instance, with the first Magic Leap.

The company also prides itself on bringing significant advancements not just in one area but in several at once (FOV, power efficiency, clarity, etc…), which is, to their say, quite unusual.

What are the potential disadvantages?

Making a system like this may be tricky. First of all, the micromirrors should be positioned so that the eyes do not notice them. I know they are two different optical systems, but to me, the approach by Gixel has some similarities with the one by LetinAR. In both cases, many small points reflect the virtual image to the eyes of the user, and in both cases, this image should appear as a single cohesive image and not as many small points. The first prototype I tried from LetinAR still made me see the various holes as halos in the image, while the latest one I tried at AWE showed huge progress in improving this. I think Gixel has a similar challenge in trying to transform these reflections from all these micromirrors into just one single virtual image.

Furthermore, the fact that the micromirrors have to modify their properties to follow the eyes may be a concern. The eyes move continuously and move very fast, so the mirrors should continuously change themselves. Not to mention the fact that to ensure the eyes see the image correctly every time, the mirrors should be able to move with very low latency. All these fast electromechanical operations, executed for a long time, may put the mirrors under strain, and I have some questions about the durability of the system. Long and detailed tests are necessary to ensure the mirrors can last for years. I also have the concern of repairability: what if just one mirror breaks? May the surrounding ones supply to their purpose? Can it be repaired?

Finally, when the glasses are turned off, you should just see the world around you with no distortions and artifacts given by the presence of micromirrors.

These are all concerns that are known to the company. The team is actively working on them.

Gixel got €5M of investment

The intriguing technology developed by Gixel (which is useful for AR gl… ok, you know it) has just got the trust of some very important investors from our industry. They are: “Oculus VR co-founder Brendan Iribe; former Chief Futurist at 20th Century Fox and Paramount, and founding team member at RED Digital Cinema, Ted Schilowitz; FlixBus founders Jochen Engert, Daniel Kraus, and André Schwämmlein; Germany’s Federal Agency for Disruptive Innovation (SPRIND); and early-stage VC firm LEA Partners”. You may have recognized some names, like Brendan and Ted: if these people who have been in our industry for ages decided to invest in this company, it means that it has something interesting to offer.

While €5M may seem a lot of money, they are nothing if you are building hardware, especially if we are talking about a new type of hardware for which there are no established manufacturing pipelines. This money will be used to improve the current technology, solve its potential issues, and evaluate how to manufacture it at scale.

If all these steps prove to be successful, the company aims to raise a much bigger Series A next year to scale manufacturing and meet industry demand.

Hands-on with Gixel prototype

When I was at AWE, I was able to have a friendly meeting with the CEO of Gixel, Felix Nienstaedt, and the Director of Strategy & Partnerships, Marcus Kuehne. Since you all like disclaimers, I’ll say that they offered me a breakfast… which, considering they just raised €5M, it is pretty disappointing… they could have taken me to eat caviar and Champagne on a yacht full of strippers, but you know, these Germans all work seriously.

Jokes apart, this is the first thing that I appreciated about the Gixel CEO: the meeting had no bullshit, no big claims. He just pointed out what he thinks are the advantages and disadvantages of their approach, what the milestones are, what they need, etc… It was all very serious and practical. This gave me a lot of confidence in the company, because it gave me the impression that these are people who know what they are doing. They know they are trying a new, different approach, they are confident in it, but they know the difficulties and are not overpromising anything. I personally think this is very important.

Talking about the product, I was able to try the current early prototype. I was given a little black cube with a single lens and a single mirror on it. You can see it in the image below:

I put these half-glasses close to my right eye until I could see what was in that single micromirror: the small image of a small animated flower. The thing that I can comment on is that the flower had a great definition and very bright colors. And the lens it was mounted on was very transparent, so I could see that small flower in augmented reality. So I can confirm that at least with one single static micromirror, the system works very well. Of course, we all know that the real problems start with many mirrors, but the fact that they took a working prototype is another sign of reliability to me.

Final impressions

I’m not as smart as Karl Guttag when we are talking about optical systems, but I know a thing or two about XR systems. So while we wait for Karl to write a post about Gixel, the thing I can say is that I find this startup very interesting. It is proposing a new approach for AR optical systems, its current basic prototype works, and it has the money and a clear roadmap for the next steps. Plus, as a European, I’m happy that it is an XR hardware company based in Europe, which is not something very common.

Now that the company has received this investment, the hardest moment begins, because it has to prove that its idea can truly deliver, that the multiple moving micromirrors approach works, and can scale to potentially millions of units. I wish good luck to the team, and I’ll keep following its developments.

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