physics

Optical see-through head-mounted display

Optical see-through head-mounted display is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Optical see-through head-mounted display rather than just read about it. In short: An optical see-through head-mounted display (OST-HMD) is a wearable device that has the capability of reflecting projected images as well as allowing the user to see through it, in contrast to typical head-mounted displays, which still use optical components, but are not see-through, such as virtual reality headsets. In some cases, this may qualify as augmented reality (AR) technology.

Key takeaways

Optical see-through head-mounted display belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Optical see-through head-mounted display to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Optical see-through head-mounted display from memory before moving on to harder problems.

Reference excerpt

An optical see-through head-mounted display (OST-HMD) is a wearable device that has the capability of reflecting projected images as well as allowing the user to see through it, in contrast to typical head-mounted displays, which still use optical components, but are not see-through, such as virtual reality headsets. In some cases, this may qualify as augmented reality (AR) technology. OHMD technology has existed since 1997 in various forms, but despite a number of attempts from industry, has yet to have had major commercial success. Commercial optical see-through head-mounted displays include Google Glass and Microsoft HoloLens. Other devices include the NVIS nVisor ST, Vuzix M300, and Meta 2 from Meta.

History See-through head-mounted displays date to 1968, when Ivan E. Sutherland demonstrated a stereoscopic head-mounted display (Ivan Sutherland's head-mounted 3D display) using half-silvered mirrors (a beam combiner) to overlay computer graphics on the real world.

Types Various techniques have existed for see-through HMDs. Most of these techniques can be summarized into two main families: "Curved Mirror" (or Curved Combiner) based and "Waveguide" or "Light-guide" based. The curved mirror technique has been used by Vuzix in their Star 1200 product, by Olympus, and by Laster Technologies. Various waveguide techniques have existed for some time. These techniques include diffraction optics, holographic optics, polarized optics, and reflective optics:

Diffractive waveguide – slanted diffraction grating elements (nanometric 10E-9). Nokia technique now licensed to Vuzix. Holographic waveguide – 3 holographic optical elements (HOE) sandwiched together (RGB). Used by Sony and Konica Minolta. Polarized waveguide – 6 multilayer coated (25–35) polarized reflectors in glass sandwich. Developed by Lumus. Reflective waveguide – A thick light guide with single semi-reflective mirror is used by Epson in their Moverio product. A curved light guide with partial-reflective segmented mirror array to out-couple the light is used by tooz technologies. "Clear-Vu" reflective waveguide – thin monolithic molded plastic w/ surface reflectors and conventional coatings developed by Optinvent and used in their ORA product. Switchable waveguide – developed by SBG Labs, now known as DigiLens.

Input devices Input devices that lend themselves to mobility and/or hands-free use are good candidates, for example:

Touchpad or buttons Compatible devices (e.g. smartphones or control unit) Speech recognition Gesture recognition Eye tracking

Recent developments

2012 On 17 April 2012, Oakley's CEO Colin Baden stated that Oakley has been working on a way to project information directly onto lenses since 1997, and has 600 patents related to the technology, many of which apply to optical specifications. On 18 June 2012, Canon announced the MR (Mixed Reality) System which simultaneously merges virtual objects with the real world at full scale and in 3D. Unlike the Google Glass, the MR System is aimed for professional use with a price tag for the headset and accompanying system is $125,000, with $25,000 in expected annual maintenance.

2013 At Maker Faire 2013, the startup company Technical Illusions unveiled castAR augmented reality glasses which are well equipped for an AR experience: infrared LEDs on the surface detect the motion of an interactive infrared wand, and a set of coils at its base are used to detect RFID chip loaded objects placed on top of it; it uses dual projectors at a framerate of 120 Hz and a retroreflective screen providing a 3D image that can be seen from all directions by the user; a camera sitting on top of the prototype glasses is incorporated for position detection, thus the virtual image changes accordingly as a user walks around the CastAR surface.

2016 The Latvian-based company NeckTec announced the smart necklace form-factor, transferring the processor and batteries into the necklace, thus making facial frame lightweight and more visually pleasing.

2018 Intel announces Vaunt, a set of smart glasses that are designed to appear like conventional glasses and are display-only, using retinal projection. The project was later shut down. Zeiss and Deutsche Telekom partners up to form tooz technologies GmbH to develop optical elements for smart glass displays.

2019 Microsoft introduced the HoloLens 2, a self-contained optical see-through HMD using holographic waveguides, with a larger field of view and improved ergonomics over the original model.

2021 Snap Inc. announced a developer-only generation of Spectacles with dual 3D waveguide displays and a 26.3° diagonal field of view, intended to overlay AR Lenses directly onto the real world.

2022 Magic Leap 2 debuted with a see-through display and a dynamic dimming system that can globally or locally dim the real-world view to improve virtual image contrast and enable basic occlusion effects.

Market structure Analytics company IHS has estimated that the shipments of smart glasses may rise from just 50,000 units in 2012 to as high as 6.6 million units in 2016. According to a survey of more than 4,600 U.S. adults conducted by Forrester Research, around 12 percent of respondents are willing to wear Google Glass or other similar device if it offers a service that piques their interest. Business Insider's BI Intelligence expects an annual sales of 21 million Google Glass units by 2018. According to reliable reports, Samsung and Microsoft are expected to develop their own version of Google Glass within six months with a price range of $200 to $500. Samsung has reportedly bought lenses from Lumus, a company based in Israel. Another source says Microsoft is negotiating with Vuzix. In 2006, Apple filed patent for its own HMD device. In July 2013, APX Labs founder Brian Ballard stated that he knows of 25-30 hardware companies who are working on their own versions of smart glasses, some of which APX is working with.

Comparison of near-eye see-through display technologies

See also Epiphany Eyewear EyeTap Open Cobalt Recon Instruments SixthSense Smartglasses Virtual retinal display

References

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Optical see-through head-mounted display

Start with the simplest possible case. Write down what Optical see-through head-mounted display claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Optical see-through head-mounted display before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Optical see-through head-mounted display ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Optical see-through head-mounted display

In research: Optical see-through head-mounted display appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Optical see-through head-mounted display in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Optical see-through head-mounted display is common in secondary-school and first-year university syllabi. It links to neighbouring topics Electronic display devices, Head-mounted displays, Mixed reality, so understanding it makes those chapters shorter.
In everyday life: Look for Optical see-through head-mounted display outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Optical see-through head-mounted display” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Optical see-through head-mounted display in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Optical see-through head-mounted display means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Optical see-through head-mounted display out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Optical see-through head-mounted display in simple terms?

Why does Optical see-through head-mounted display matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Optical see-through head-mounted display?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Optical see-through head-mounted display.