TDK Will Demo Retinal-Projection Glasses With a 150 nm Mirror Inside the Lens

TDK will show a working smart-glasses prototype at CEATEC 2026 starting Oct. 13 that draws a monochrome image straight onto the wearer's retina using a 150-nanometer-thick mirror built into the lens. Full colour and mass production are targets for the coming years, not features of the demo.

The company's announcement, as summarised by Japan's Impress Watch, describes a flat meta-optic mirror: a surface of nanoscale reflectors, each set to bounce laser light at its own angle so beams arriving from different directions all converge on the eye. Impress reports about 80 percent transmittance for visible light, which is why the lens can look like ordinary eyewear. TDK also says people facing the wearer see no leaked image, and that the sub-wavelength structure suppresses the rainbow interference patterns that fine optical structures tend to produce.

What the prototype is and is not

Impress says the embedded mirror replaces the curved external mirror that retinal-projection glasses previously needed. Putting a flat mirror inside the lens is what lets the frame resemble standard eyeglasses. The trade is that the demo is monochrome, and TDK has given a timetable only in years.

Item	Figure	Status
Meta-optic mirror thickness	150 nm	Prototype
Visible-light transmittance	About 80%	Prototype
Colour output	Monochrome	Full colour in development
Public showings	CEATEC from Oct. 13; Electronica on Nov. 10	Scheduled

Russia's 3DNews adds two details Impress does not carry: a 4K resolution target and the Electronica date. Treat the resolution as a goal reported by one outlet, since neither source gives a measured resolution, brightness or field of view for the prototype.

The laser half of the system

The mirror is only the optical end. The light has to come from somewhere, and TDK has a partner for that. It signed a business cooperation agreement with QD Laser, according to Impress, combining QD Laser's retinal projection technology with TDK's laser light sources, control devices and meta-optic mirrors.

TDK's earlier work gives a sense of the scale involved. When it demonstrated glasses at CEATEC 2022, electronica 2022 and CES 2023, the full-colour laser module measured 5.5 mm by 10.8 mm by 2.6 mm, weighed 0.38 grams and produced 16.2 million colours, per eeNews Europe. A planar lightwave circuit in that module was developed jointly with Nippon Telegraph and Telephone Corporation. The module was pitched at a wider field of view than waveguide displays, because it projects directly into both eyes.

The number that matters here is not the 150 nm but the figures neither source supplies: brightness, field of view and eyebox, the zone within which the pupil can sit and still see the image. A mirror that works only when the pupil sits in one place is a lab result, and one that tolerates eye movement is a product.

Display is half of a glasses product. Our piece on openTPU showed memory bandwidth setting every token rate on a small accelerator, and a pair of glasses has far less room for memory than that card. Startups are already selling the other extreme: Ghost raised $11 million for a $3,499 screenless computer.

What would change my read is a measured eyebox and a full-colour sample at CEATEC. TDK has already said the colour demonstration and mass production are some years off; the Oct. 13 booth shows whether the monochrome prototype is steady enough to wear.