An optical head-mounted display (OHMD) is a wearable device that has the capability of reflecting projected images as well as allowing the user to see through it. 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.
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:
Head-mounted displays are not designed to be workstations, and traditional input devices such as keyboards do not support the concept of smart glasses. Input devices that lend themselves to mobility and/or hands-free use are good candidates, for example:
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. [10] 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. [11] Business Insider's BI Intelligence expects an annual sales of 21 million Google Glass units by 2018. [12]
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. [13]
In 2006, Apple filed patent for its own HMD device. [14]
In July 2013, APX Labs founder and CEO 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. [15]
 | This section needs additional citations for verification .(July 2013) |
| Combiner technology | Size | Eye box | FOV | Limits / Requirements | Example |
|---|---|---|---|---|---|
| Flat combiner 45 degrees | Thick | Medium | Medium | Traditional design | Vuzix, Google Glass |
| Curved combiner | Thick | Large | Large | Classical bug-eye design | Many products (see through and occlusion) |
| Phase conjugate material | Thick | Medium | Medium | Very bulky | OdaLab |
| Buried Fresnel combiner | Thin | Large | Medium | Parasitic diffraction effects | The Technology Partnership (TTP) |
| Cascaded prism/mirror combiner | Variable | Medium to Large | Medium | Louver effects | Lumus, Optinvent |
| Free form TIR combiner | Medium | Large | Medium | Bulky glass combiner | Canon, Verizon & Kopin (see through and occlusion) |
| Diffractive combiner with EPE | Very thin | Very large | Medium | Haze effects, parasitic effects, difficult to replicate | Nokia / Vuzix |
| Holographic waveguide combiner | Very thin | Medium to Large in H | Medium | Requires volume holographic materials | Sony |
| Holographic light guide combiner | Medium | Small in V | Medium | Requires volume holographic materials | Konica Minolta |
| Combo diffuser/contact lens | Thin (glasses) | Very large | Very large | Requires contact lens + glasses | Innovega & EPFL |
| Tapered opaque light guide | Medium | Small | Small | Image can be relocated | Olympus |
Augmented reality (AR) is an interactive experience that combines the real world and computer-generated content. The content can span multiple sensory modalities, including visual, auditory, haptic, somatosensory and olfactory. AR can be defined as a system that incorporates three basic features: a combination of real and virtual worlds, real-time interaction, and accurate 3D registration of virtual and real objects. The overlaid sensory information can be constructive, or destructive. This experience is seamlessly interwoven with the physical world such that it is perceived as an immersive aspect of the real environment. In this way, augmented reality alters one's ongoing perception of a real-world environment, whereas virtual reality completely replaces the user's real-world environment with a simulated one.
Liquid crystal on silicon is a miniaturized reflective active-matrix liquid-crystal display or "microdisplay" using a liquid crystal layer on top of a silicon backplane. It is also referred to as a spatial light modulator. LCoS was initially developed for projection televisions but is now used for wavelength selective switching, structured illumination, near-eye displays and optical pulse shaping. By way of comparison, some LCD projectors use transmissive LCD, allowing light to pass through the liquid crystal.
A 3D display is a display device capable of conveying depth to the viewer. Many 3D displays are stereoscopic displays, which produce a basic 3D effect by means of stereopsis, but can cause eye strain and visual fatigue. Newer 3D displays such as holographic and light field displays produce a more realistic 3D effect by combining stereopsis and accurate focal length for the displayed content. Newer 3D displays in this manner cause less visual fatigue than classical stereoscopic displays.
A head-mounted display (HMD) is a display device, worn on the head or as part of a helmet, that has a small display optic in front of one or each eye. An HMD has many uses including gaming, aviation, engineering, and medicine. Virtual reality headsets are HMDs combined with IMUs. There is also an optical head-mounted display (OHMD), which is a wearable display that can reflect projected images and allows a user to see through it.
A virtual retinal display (VRD), also known as a retinal scan display (RSD) or retinal projector (RP), is a display technology that draws a raster display directly onto the retina of the eye.
An optical waveguide is a physical structure that guides electromagnetic waves in the optical spectrum. Common types of optical waveguides include optical fiber waveguides, transparent dielectric waveguides made of plastic and glass, liquid light guides, and liquid waveguides.
A holographic grating is a type of diffraction grating formed by an interference-fringe field of two laser beams whose standing-wave pattern is exposed to a set of photosensitive materials. The exposure triggers chemical processes within the sample and results in the formation of a periodic structure that has the same periodicity of the recorded pattern. One of the most interesting features of these structures is their versatility and tunability as the optical response strongly depends on the blend of used materials, and their interactions with light during, and after, the recording procedure.
Himax Technologies, Inc. is a leading supplier and fabless semiconductor manufacturer headquartered in Tainan City, Taiwan founded on 12 June 2001. The company is publicly traded and listed on the Nasdaq Stock Market under the symbol HIMX. The Himax Technologies Limited functions as a holding under the Cayman Islands Companies Law.
Vuzix is an American multinational technology company headquartered in Rochester, New York and founded by Paul Travers in 1997. Vuzix is a supplier of wearable virtual reality and augmented reality display technology. Vuzix manufactures and sells computer display devices and software. Vuzix head-mounted displays are marketed towards mobile and immersive augmented reality applications, such as 3D gaming, manufacturing training, and military tactical equipment. On January 5, 2015, Intel acquired 30% of Vuzix's stock for $24.8 million.
Holographic optical element (HOE) is an optical component (mirror, lens, directional diffuser, etc.) that produces holographic images using principles of diffraction. HOE is most commonly used in transparent displays, 3D imaging, and certain scanning technologies. The shape and structure of the HOE is dependent on the piece of hardware it is needed for, and the coupled wave theory is a common tool used to calculate the diffraction efficiency or grating volume that helps with the design of an HOE. Early concepts of the holographic optical element can be traced back to the mid-1900s, coinciding closely with the start of holography coined by Dennis Gabor. The application of 3D visualization and displays is ultimately the end goal of the HOE; however, the cost and complexity of the device has hindered the rapid development toward full 3D visualization. The HOE is also used in the development of augmented reality(AR) by companies such as Google with Google Glass or in research universities that look to utilize HOEs to create 3D imaging without the use of eye-wear or head-wear. Furthermore, the ability of the HOE to allow for transparent displays have caught the attention of the US military in its development of better head-up displays (HUD) which is used to display crucial information for aircraft pilots.
Recon Instruments was a Canadian technology company that produced smartglasses and wearable displays marketed by the company as "heads-up displays" for sports. Recon's products delivered live activity metrics, GPS maps, and notifications directly to the user's eye. Recon's first heads-up display offering was released commercially in October 2010, roughly a year and a half before Google introduced Google Glass.
zSpace is a technology firm based in San Jose, California that combines elements of virtual and augmented reality in a computer. zSpace mostly provides AR/VR technology to the education market. It allows teachers and learners to interact with simulated objects in virtual environments.
Smartglasses or smart glasses are eye or head-worn wearable computers that offer useful capabilities to the user. Many smartglasses include displays that add information alongside or to what the wearer sees. Alternatively, smartglasses are sometimes defined as glasses that are able to change their optical properties, such as smart sunglasses that are programmed to change tint by electronic means. Alternatively, smartglasses are sometimes defined as glasses that include headphone functionality.
castAR was a Palo Alto–based technology startup company founded in March 2013 by Jeri Ellsworth and Rick Johnson. Its first product was to be the castAR, a pair of augmented reality and virtual reality glasses. castAR was a founding member of the nonprofit Immersive Technology Alliance.
Windows Mixed Reality is a platform introduced as part of the Windows 10 and 11 operating system, which provides augmented reality and virtual reality experiences with compatible head-mounted displays.
Microsoft HoloLens is an augmented reality (AR)/mixed reality (MR) headset developed and manufactured by Microsoft. HoloLens runs the Windows Mixed Reality platform under the Windows 10 operating system. Some of the positional tracking technology used in HoloLens can trace its lineage to the Microsoft Kinect, an accessory for Microsoft's Xbox 360 and Xbox One game consoles that was introduced in 2010.
Lumus is an Israeli-based augmented reality company headquartered in Ness Ziona, Israel. Founded in 2000, Lumus has developed technology for see-through wearable displays, via its patented Light-guide Optical Element (LOE) platform to market producers of smart glasses and augmented reality eyewear.
Commercial augmented reality (CAR) describes augmented reality (AR) applications that support various B2B (Business-to-Business) and B2C (Business-to-Consumer) commercial activities, particularly for the retail industry. The use of CAR started in 2010 with virtual dressing rooms for E-commerce.
Ray-Ban Stories are smartglasses created as a collaboration between Meta Platforms and EssilorLuxottica. The product includes two cameras, open-ear speakers, a microphone, and touchpad, all built into the frame. The glasses, announced in August 2020 and released on September 9, 2021, had a controversial reception stemming from mistrust over Facebook’s privacy controls. The small size of the recording indicator light has also led to controversy post-release. Ray-Ban Stories are the latest in a line of smartglasses released by major companies including Snap Inc and Google and are designed as one component of Facebook’s plans for a metaverse. Unlike smart glasses previously created by other companies, the Ray-Ban Stories do not include any HUD or AR head-mounted display.
Vergence-accommodation conflict (VAC), also known as accommodation-vergence conflict, is a visual phenomenon that occurs when the brain receives mismatching cues between vergence and accommodation of the eye. This commonly occurs in virtual reality devices, augmented reality devices, 3D movies, and other types of stereoscopic displays and autostereoscopic displays. The effect can be unpleasant and cause eye strain.