Direct retinal projection display for smart glasses using a meta-optic mirror | Hacker News Reader

Direct retinal projection display for smart glasses using a meta-optic mirror

tdk.com

136 pointsbookofjoe76 comments

Neat, but hardly a world first (the original title said "...the world’s first direct retinal projection display...")

I first read about direct retinal projection displays (using oscillating mirrors no less) in Mondo 2000 [^1]

Hard to find much on the "Private Eye" hardware as I guess Reflection Technology (the manufacturer) went outta business in the mid 90's

But a 700x280 display painted onto your retina that looked like a full-ish size display hovering in space nonetheless, and downright epic for 1989

[^1]: https://microship.com/winnelife-interview-with-steve-roberts...

For the curious, a bit more info and some pics on these sites

https://glassdevelopment.wordpress.com/2014/04/17/hmd-histor...

https://artsandculture.google.com/asset/reflection-technolog...

"TDK demonstrates the world’s first direct retinal projection display for smart glasses using a meta-optic mirror". The qualifier is different. "using a meta-optic mirror" versus "using oscillating mirrors"

I appreciate your comment on the history.

lol, qualified claims are funny.

I remember reading that Sunnyvale CA was the safest city in the US!

I looked at wikipedia, and they say that too.

> Sunnyvale has consistently ranked as one of the safest ten cities (for cities of similar size) in the United States according to the FBI's crime reports.

https://en.wikipedia.org/wiki/Sunnyvale,_California#Crime

also: "According to Sunnyvale's Department of Public Safety, confirmed gang members make up less than one percent of the population"

With the qualifiers, is it actually safe there? :)

Don't forget the Sony DSC-HX99 retinal projection camera kit, built with QD Laser. They had a custom RETISSA NEOVIEWER commissioned for the camera to allow for low-vision users to leverage it for photography.

Sadly no longer available. I've seen through one and it was vividly clear and detailed without my glasses on at all and it felt so gamechanging to have that kind of display technology in my hands.

https://electronics.sony.com/imaging/compact-cameras/all-vlo...

It's now transformed though, into the RETISSA VIEWCLEAR for your phone - https://retissa-vc.qdlaser.com/en/

Always regretted not getting one of those cameras when they were available.

You can get one here:

https://www.sony.com/electronics/support/articles/00297030

https://imgur.com/a/RF6vcVM

>Sadly no longer available.

You can get one here: https://www.sony.com/electronics/support/articles/00297030

https://imgur.com/a/RF6vcVM

I contacted Bosch in 2020 about buying BML500P retinal projectors in bulk, but they postponed the sale for several months because they were in talks with a major undisclosed customer about potentially exclusive rights to the patent. I never heard back.

Ominous…!

I saw a demo retinal dispaly at the university of washington in the late 90s.

At the HITlab?

I interviewed Dan Bricklin in '88 or '89 (for a magazine). Trippy dude. Lots of ideas.

Bricklin stated the optic nerve is exposed brain. So that when a laser projects an imagine directly on to the retina, it's like programming the brain.

Nope.

I decided right then and there I never needed a laser pointing at my eye ball.

Yeah at the hitlab. I had some friends working on a few things during school there (their school, i was in art school).

I heard tell of a guy with massive cornea damage in one eye, some low-level university employee (facilities or something). They invited him to try it out, could see the image clear as day.

Lots of cool stuff being worked on at the HITlab those days. Seemed to kinda peter out.. or at least get less press.. in the years since.

The lens seems pretty similiar to PinTILT, who embed miniature reflectors in the lens - there's a nice whitepaper available by email on their site.

* https://letinar.com/en/pintilt

I wrote a short story years ago about a tech CEO going to trial over a similar technology that turned out to mass-blind people. Just food for thought I guess.

I remember the movie, starring Steve Martin...

Don’t be the jerk, man

I'd suggest something more realistc than a CEO suffering any consequences for their actions.

I have a quite badly displaced retina due to a detachment. I wonder if technology like this could be used in conjunction with mapping the distorted retina in order to obtain a correct perceived image.

I have a friend with the same issue and thought the same thing.

Comment above points to interesting Japanese device too:

https://news.ycombinator.com/item?id=49977339

Hello I also suffer from a partially detached retina. I also have thought about what you proposed. I think the technical challenge here is that our brains adapt the broken input signal to correct the vision we perceive for the displacement so you’re not just reverse engineering the damaged retina but also the brain signal correction that takes place

https://prima.science.xyz/

just to let you know there is prima from science , but they are for restoring vision. I think over time problem like yours could be solved by something like this .

I know "what does it look like" is open to mis-interpretation, but I think all of us would like something approximating to artwork which shows what you as a wearer "see" through this mechanism.

I don't worry about the fashion sense of the frames and lenses: I wan't to understand the perceptual effect on reality: Whats the overlay like?

played with one of these 'retinal displays' back in the late 90s at the university of washington. Pretty crazy stuff, apparently some guy with massive cornea damage was able to see the retinal projection clearly. At the time it was just monochrome and fairly low resolution (by todays standards) but very exciting.

This looks strikingly similar to my 2017/20 patent:

https://kemendo.com/pdfs/USPatent10757400.pdf

Pretty much all my patents are being infringed at this point.

Lesson to anyone getting patents, they don’t matter unless you have $100M to fight Microsoft or oracle with. At that point might as well just keep your 100M and forget it

Did you file for a patent in Japan? Foreign countries are not bound by United States patents; U.S. patent rights only apply within the United States.

Fair point

Most countries, including the Japan and the US, recognize a patent in another country for filing purposes. Which is to say, if you need to sue someone in Japan, yes you need a patent in Japan. However, you bring your US patent to the Japan Patent Office and they consider that as your file date and so you can sue for infringements that happen before your patent in Japan was issued.

If this is actually useful for you, of course, you need a patent lawyer in the specific country you're talking about, which is not cheap, and that's why the other posters said millions of dollars. Patents are not worth it for most people because you still have to pay lawyers to get anything out of them. You also pay for your time in court, acting as witness and testifying and watching court proceedings instead of doing your own business.

I learned that lesson too. But I also learned that you get what you pay for in terms of the patent attorney's skill in crafting claims.

When you file a patent the patent attorneys tell you how critical it is to do so.

When someone infringes a patent, especially if you’re not commercializing your patent, the patent attorneys tell you, “wow, that looks really tough.”

It’s a big company game at this point, in general, or you’d need something that drives an immense amount of value before the patenting seems worth it, as far as I can tell.

Maybe we should get rid of patent protection. We already have enough welfare for megacorps, and this is just another form of it.

This is the solution, they do not push for innovation anymore (if ever).

(ignoring the snark but valid point)

To the contrary, innovation is proceeding full speed, despite patents. The only thing patents are doing is 1. enriching the lawyers on creation, 2. restraining law abiding innovators in country (meaning all other countries will proceed to ignore it anyway), 3. give the advantage to all other countries, and 4. enrich the lawyers again if they can find one of the in-country infringements to pursue (again ignoring all the others).

None of these outcomes is beneficial. The system is broken and antiquated. Ditch it.

5. Prevent the consumer-friendly pricing effects of competition.

Honestly, this would have pretty positive effects on costs of medicine, replacement parts for machinery, etc. It definitely hampers the regulatory capture moat that these companies build.

This is exactly the wrong way to be moving. We should be properly enforcing our laws on megacorps, not just shrugging and throwing them out entirely because it's just toooooo haaaaard to actually stop these companies from breaking them.

Without patent protection, any individual or small business that comes up with something new and (currently) patentable would have no recourse whatsoever. The megacorps could just start producing whatever it is as soon as they find out about it, and outcompete the actual creator with massive economies of scale and the ability to take a loss effectively forever on any given product.

>This is exactly the wrong way to be moving.

Sure, if you live with an 1800s era mentality about who invents things. This is no longer the era of Thomas Edison and the individual inventor. If our laws don't meaningfully reflect the way our lives are lived now, they won't be useful frameworks. I think your proposal may be about 2 centuries behind the times.

>Without patent protection, any individual or small business that comes up with something new and (currently) patentable would have no recourse whatsoever. The megacorps could just start producing whatever it is as soon as they find out about it, and outcompete the actual creator with massive economies of scale and the ability to take a loss effectively forever on any given product.

It seems like they do this anyway, and patent protections mean high prices for consumers on patent-protected products. Given that in the mid-2020s, the corporation:individual ratio patents is ~18.5:1 (up from 4:1 in the 1970s), I see the benefit gradient being more pro-consumer by getting rid of them.

> This is no longer the era of Thomas Edison and the individual inventor.

I get your point, but Edison is the worst possible example to use here.

You're describing the system as it exists today, where the powerful have been allowed to run rampant, suppressing competition, for decades. Not to mention the loss of trust in the patent system as a whole, due to things like software patents being transparently corruptions of the system.

If it were possible for an individual to profit from their patent today as they would have in the 1970s, it's much more likely that people would seek patents.

I figured the ratio would be even more distorted like 1000:1.

Can’t imagine individuals getting patents unless they’re owners of a small business. Even then, don’t see how they’d have sufficient resources for defending them.

Except that the purpose of patents is not to be "pro-consumer", at least in the US Constitution, it's to "To promote the Progress of Science and useful Arts".

The purpose is to provide an incentive to creators to reveal their inventions and make them available to the public and other creators, instead of keeping them as trade secrets.

>Except that the purpose of patents is not to be "pro-consumer", at least in the US Constitution, it's to "To promote the Progress of Science and useful Arts".

Perfect reason to abandon patents. American innovation has ascended to the top of the species; it doesn't need additional protection.

> American innovation has ascended to the top of the species

What on earth does that mean and how is it relevant? Are you trying to say that there is no more "[P]rogress of Science and useful Arts" left to be made?

Patents protect the innovators; American tech is the best on the planet; the bust humans have to offer, in aggregate (whether measured by patents or money generated by them). There is obviously progress to be made, I just believe that American technologists no longer need patent protections. We are not a small upstart country anymore; we have scaled.

In fact, not only have we scaled as a country and an economy, we are now in the enshittification + rent seeking phase of capitalism, which is precisely why patent protections should be discarded.

OK sooo... is there a way to get investors to cover the legal costs?

Or just outright sell the patents to a competing big company and let them duke it out. Now at least you end up with some money.

When I wanted to file a patent, the attorneys told me it was only good as my ability to enforce it, which really means how much money I have vs the other guy

They are pretty inarguable prior art for anyone who wants to compete with TDK.

Good. Patents should not reward people for simply being the first to have an idea that others can easily discover independently.

>Pretty much all [...] are being infringed at this point.

So, funny you say that. You know those AI companies that seem to have really good training data...

Skimming that patent, I see little indication that you solved the actual practical problems with making something like this; you wrote down the problem statement, not the solution. This should not have been granted a patent.

Ah, glad you skimmed it ;)

Snowcrash here we go! ;)

Isn’t this dangerous for the eyes?

That's the first thing i have searched the current blue screen have already caused enough damage to eyes. but ig it's still in early prototype and i would be appreciated if they provided the affects that it might causes to eyes.

Blue light from screens does not damage eyes. https://scienceinsights.org/does-blue-light-actually-damage-...

i thought it wasn't about the eyes but about the Melatonin production, sleep and circadian rhythm.

As exemplared by the person I was replying to, there are folks who think blue light from screens is specifically damaging to the eyes.

That has been proven to be false, too. The blueness of the light doesn't matter, the brightness does. Any bright light might affect melatonin production and circadian rhythms.

Selling blue-light filter coatings is a big business, though.

>That has been proven to be false, too.

by who?

"While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours)." https://www.health.harvard.edu/healthy-aging-and-longevity/b...

"Evening residential illumination possesses the capacity to impair sleep quality via the suppression of endogenous melatonin production, a process largely driven by short-wavelength (blue) light." https://www.nature.com/articles/s41598-025-29882-7

"Blue light waves come from fluorescent and LED lights and back-lit electronic screens on televisions, computers, tablets, and cell phones. Remember, exposure to these lighted screens during the sensitive period can make it difficult for you to fall asleep at night or can wake you up too early" https://www.cdc.gov/niosh/work-hour-training-for-nurses/long...

"Blue light had stronger suppression effects, particularly in younger participants and men. These results underscore blue light’s disruptive effects on circadian health and highlight red light as a less disruptive alternative for nighttime environments." https://pmc.ncbi.nlm.nih.gov/articles/PMC12113466/

I find meta-analysis are better for understanding the current state of research on a particular topic.

"A systematic search of PubMed, Scopus, and Web of Science identified randomized controlled trials (RCTs) from 2010 to 2024. Eligible studies enrolled adults using BBGs before bedtime and reported actigraphy-derived outcomes. Random-effects meta-analysis was performed using the generic inverse variance method. The review was registered in PROSPERO (CRD420251034611).

Results

Three double-blind crossover RCTs (n = 49) were included. BBGs showed a non-significant reduction in SOL (MD = −4.86 min; 95% CI: −20.23 to 10.52; p = 0.54) and a non-significant increase in TST (MD = 8.75 min; 95% CI: −35.31 to 52.82; p = 0.70). No significant effects were found for SE (MD = −0.61; 95% CI: −7.58 to 6.35; p = 0.86) or WASO (MD = −1.47; 95% CI: −14.94 to 11.99; p = 0.83). Heterogeneity was low (I2 = 0%).

Conclusion

BBGs may provide small improvements in sleep, but current evidence from RCTs does not support significant effects. Larger, well-powered trials with standardized protocols are needed."

- Efficacy of blue-light blocking glasses on actigraphic sleep outcomes: a systematic review and meta-analysis of randomized controlled crossover trials - https://doi.org/10.3389/fneur.2025.1699303

given that phonescreens do not really dim the brightness and still flash lights in your face at full power just at slower intervalls does in a way confirm the point.

(See PWM dimming)

And a redlight filter just lowers the total brightness by shutting down the blue LED

that addresses the parent's last sentence, about blue light glasses, but not the "The blueness of the light doesn't matter" part, which is what all of my quotes addressed.

https://www.economist.com/science-and-technology/2026/09/04/...

Light being from a laser does not automatically make it more dangerous. You can even shine a regular class IIIa laser pointer, with warning label still intact, directly into your eye and you'll blink long before it will do any damage.

The issue is intensity of light. These retinal projector lasers are not intense enough to damage your eye. A regular light at the same intensity as a powerful laser would damage your eyes just as much. It's just a lot harder to create a regular light that can reach that level of intensity.

I think the tricky part is if they start cranking up the intensity to counter it being scanned sequentially over a larger area...

First, what is the fail-safe in case the scanning mechanism fails? I.e. is the intensity safe if the beam becomes stationary? Or does it guarantee it goes dark when not properly scanning?

Second, what is the safe intensity limit for the brief visits to each target pixel area? As the scanned area increases, you need higher intensity to maintain the same visual brightness with a shorter exposure for any one spot. At some limit, is the pixel to area ratio too low and this intensity too great?

Third, does the optical path through the cornea and lens have any hot-spot where you have to also worry about peak flux with this projection technique?

Would be good if the hardware itself would get damaged by non-scanning laser before eye would.

Yeah I saw the main image of a green laser being projected into the eye and thought "nah, I'm good."

IBM was working on this in the early 90s[1], and had working demos in the late 90s/early 2000s. I'm pretty sure we would have heard about health risks by now

[1]: https://patents.google.com/patent/EP0562742A1/

"The current meta-optic mirror supports monochrome operation."

I would love monochromatic vector(not raster) HUD in my glasses. I could play the original Asteroids. Bah, bah, bah bah. Pew, pew!

Asteroids is classic, but for monochrome vector games I would vote for the tank-vs-tank game 'Battlezone', especially if they could do separate images per eye and allow for stereoscopic rendering.

Hopefully they add a color model so we can play Tempest.

That's so cool finally actually glasses instead of sunglasses!

this is cool tech, but I don't think display glasses will fully take off until head tracking/movement compensation is built-in (AR feature)

otherwise even just walking around causes the content to bounce around annoyingly

Can't wait for a real eyePhone.

Shut up and take my money!

This is great, can't wait.

Now you can get the ghost effect directly to your retina.

oh, wait!

TLDR: They demoed a direct retinal projection display with a thin, transparent mirror embedded in the lens, enabling glasses that look more like everyday eyewear while reducing costs compared with waveguide-based designs.

This Japanese article has a few more details: https://www.watch.impress.co.jp/docs/news/2145266.html

This picture (with English text) has a bit of the detail showing their reflector structure, which is also in one of the pictures of your Japanese page:

https://www.tdk.com/system/files/featured_stories/features-o...

Reply on news.ycombinator.com