Editing Augmented reality (section)

==Displays==
[[File:MicrosoftHoloLensBloomGesture.JPG|thumb|alt= Photograph of a man wearing an augmented reality headset| A man wearing an augmented reality headset]]
Augmented reality requires a head-mounted display or a handheld device, which includes a processor, display, sensors, and one or more input devices. Modern [[mobile computing]] devices like [[smartphone]]s and [[tablet computer]]s contain these elements, which often include a camera and microelectromechanical systems ([[MEMS]]) sensors such as an [[accelerometer]], [[GPS]], and [[Digital magnetic compass|solid state compass]].<ref>{{Cite web |url=http://www.technologyreview.com/news/428654/augmented-reality-is-finally-getting-real/ |title=Augmented Reality Is Finally Getting Real |last=Metz |first=Rachael |date=2 August 2012 |website=technologyreview.com |access-date=18 June 2019}}</ref><ref>{{cite journal|title=Benchmarking Built-In Tracking Systems for Indoor AR Applications on Popular Mobile Devices|journal= Sensors|date=2022|doi= 10.3390/s22145382|doi-access= free|last1= Marino|first1= Emanuele|last2= Bruno|first2= Fabio|last3= Barbieri|first3= Loris|last4= Lagudi|first4= Antonio|volume= 22|issue= 14|page= 5382|pmid= 35891058|pmc= 9320911|bibcode= 2022Senso..22.5382M}}</ref>

Various technologies can be used to display augmented reality, including [[optical head-mounted display|optical see-through head mounted displays]], [[computer monitor|monitors]], and [[mobile device|handheld devices]]. Two of the display technologies used in augmented reality are diffractive [[Waveguide (optics)|waveguides]] and reflective waveguides.

===Head-mounted displays===
A [[head-mounted display]] (HMD) is a display device worn on the forehead, such as a harness or [[Helmet-mounted display|helmet-mounted]]. HMDs place images of virtual objects over the user's field of view. Augmented reality HMDs are either optical see-through or video passthrough.<ref name="j124">{{cite web | last=Boland | first=Mike | title=Passthrough vs. Seethrough AR: The Answer is 'Both' | website=AR Insider | date=2024-11-07 | url=https://arinsider.co/2024/11/07/passthrough-vs-seethrough-ar-the-answer-is-both/ | access-date=2025-04-21}}</ref><ref name="c649">{{cite conference | last=Rolland | first=Jannick P. | last2=Holloway | first2=Richard L. | last3=Fuchs | first3=Henry | title=Comparison of optical and video see-through, head-mounted displays | date=1995-12-21 | doi=10.1117/12.197322 | url=https://www.spiedigitallibrary.org/redirect/proceedings/proceeding?articleid=981546 | access-date=2025-04-21 | page=293–307| url-access=subscription }}</ref> Modern HMDs often employ sensors for six [[Degrees of freedom (mechanics)|degrees of freedom]] monitoring that allow the system to align virtual information to the physical world and adjust accordingly with the user's head movements.<ref>{{Cite web |url=http://www.eweek.com/c/a/Security/Fleet-Week-Office-of-Naval-Research-Technology/4/ |title=Fleet Week: Office of Naval Research Technology |date=28 May 2012 |website=eweek.com |access-date=18 June 2019}}</ref><ref>Rolland, Jannick; Baillott, Yohan; Goon, Alexei.[https://web.archive.org/web/20200227120212/https://pdfs.semanticscholar.org/ce53/48128f94f3383bdc4eb15fb4eaf3721d521f.pdf A Survey of Tracking Technology for Virtual Environments], Center for Research and Education in Optics and Lasers, University of Central Florida.</ref><ref>{{Cite web |url=http://campar.in.tum.de/twiki/pub/Chair/TeachingSs07ArProseminar/1_Display-Systems_Klepper_Report.pdf |title=Augmented Reality - Display Systems |last=Klepper |first=Sebastian |website=campar.in.tum.de |archive-url=https://web.archive.org/web/20130128175343/http://campar.in.tum.de/twiki/pub/Chair/TeachingSs07ArProseminar/1_Display-Systems_Klepper_Report.pdf |archive-date=28 January 2013 |url-status=dead |access-date=18 June 2019}}</ref> When using AR technology, the HMDs only require relatively small displays. In this situation, [[liquid crystal on silicon]] (LCOS) and micro-OLED (organic light-emitting diodes) are commonly used.<ref>{{Cite journal |last=Komura |first=Shinichi |date=2024-07-19 |title=Optics of AR/VR using liquid crystals |journal=Molecular Crystals and Liquid Crystals |volume=768 |issue=17 |language=en |pages=1014–1039 |doi=10.1080/15421406.2024.2379694 |issn=1542-1406|doi-access=free |bibcode=2024MCLC..768.1014K }}</ref> HMDs can provide VR users with mobile and collaborative experiences.<ref>{{cite journal |last1=Rolland |first1=Jannick P. |last2=Biocca |first2=Frank |last3=Hamza-Lup |first3=Felix |last4=Ha |first4=Yanggang |last5=Martins |first5=Ricardo |title=Development of Head-Mounted Projection Displays for Distributed, Collaborative, Augmented Reality Applications |journal=Presence: Teleoperators and Virtual Environments |date=October 2005 |volume=14 |issue=5 |pages=528–549 |doi=10.1162/105474605774918741 |s2cid=5328957 |url=https://stars.library.ucf.edu/facultybib2000/5607 |arxiv=1902.07769 }}</ref> Specific providers, such as [[uSens]] and [[Gestigon]], include [[Gesture recognition|gesture controls]] for full virtual [[Immersion (virtual reality)|immersion]].<ref>{{cite web|title=Gestigon Gesture Tracking – TechCrunch Disrupt|url=https://techcrunch.com/video/gestigon-gesture-tracking/517762030/|website=TechCrunch|access-date=11 October 2016}}</ref><ref>{{cite web|last1=Matney|first1=Lucas|title=uSens shows off new tracking sensors that aim to deliver richer experiences for mobile VR|url=https://techcrunch.com/2016/08/29/usens-unveils-vr-sensor-modules-with-hand-tracking-and-mobile-positional-tracking-tech-baked-in/|website=TechCrunch|date=29 August 2016 |access-date=29 August 2016}}</ref>

AR headsets typically have a field of view of about 30 to 50 degrees per eye.<ref name="x344">{{cite web | last=Crisostomo | first=Christian | title=Introduction To AR Headsets Technology: The Field Of View | website=ARPost | date=2018-09-27 | url=https://arpost.co/2018/09/27/introduction-to-ar-headsets-technology-the-field-of-view/ | access-date=2025-04-21}}</ref>

[[Vuzix]] is a company that has produced a number of head-worn optical see through displays marketed for augmented reality.<ref>{{cite web |title=Images Of The Vuzix STAR 1200 Augmented Reality Glasses |url=https://techcrunch.com/2011/06/04/images-of-the-vuzix-star-1200-augmented-reality-glasses/ |website=TechCrunch |date=5 June 2011 |access-date=26 March 2024}}</ref><ref>{{cite web |title=Vuzix Blade AR glasses are the next-gen Google Glass we've all been waiting for |date=9 January 2018 |url=https://www.theverge.com/2018/1/9/16869174/vuzix-blade-ar-glasses-augmented-reality-amazon-alexa-ai-ces-2018 |access-date=26 March 2024}}</ref><ref>{{cite web |title=Hands On: Vuzix's No-Nonsense AR Smart Glasses |date=28 February 2017 |url=https://www.pcmag.com/news/hands-on-vuzixs-no-nonsense-ar-smart-glasses |access-date=26 March 2024}}</ref>

Near-eye augmented reality devices can be used as portable head-up displays as they can show data, information, and images while the user views the real world. This is basically what a head-up display does; however, practically speaking, augmented reality is expected to include registration and tracking between the superimposed perceptions, sensations, information, data, and images and some portion of the real world.<ref>{{Cite web|title = What is Augmented Reality (AR): Augmented Reality Defined, iPhone Augmented Reality Apps and Games and More|url = http://www.digitaltrends.com/features/what-is-augmented-reality-iphone-apps-games-flash-yelp-android-ar-software-and-more/|website = [[Digital Trends]]|access-date = 8 October 2015|date = 3 November 2009}}</ref>

===AR glasses===
{{Update section|date=August 2024}}
AR displays can be rendered on devices resembling eyeglasses. Versions include eyewear that employs cameras to intercept the real world view and re-display its augmented view through the eyepieces<ref>Grifatini, Kristina. [http://www.technologyreview.com/news/421606/augmented-reality-goggles/ Augmented Reality Goggles], ''Technology Review'' 10 November 2010.</ref> and devices in which the AR imagery is projected through or reflected off the surfaces of the eyewear lens pieces.<ref>Arthur, Charles. [https://www.theguardian.com/technology/2012/sep/10/augmented-reality-glasses-google-project UK company's 'augmented reality' glasses could be better than Google's], ''The Guardian'', 10 September 2012.</ref><ref>Gannes, Liz. {{cite web |url=http://allthingsd.com/20120404/google-unveils-project-glass-wearable-augmented-reality-glasses/ |title=Google Unveils Project Glass: Wearable Augmented-Reality Glasses |work=allthingsd.com |access-date=4 April 2012}}, All Things D.</ref><ref>Benedetti, Winda. [https://web.archive.org/web/20120823000655/https://www.nbcnews.com/technology/ingame/xbox-leak-reveals-kinect-2-augmented-reality-glasses-833583 Xbox leak reveals Kinect 2, augmented reality glasses] ''NBC News''. Retrieved 23 August 2012.</ref>

The [[EyeTap]] (also known as Generation-2 Glass<ref name="GlassEyes">[https://web.archive.org/web/20131004212812/http://wearcam.org/glass.pdf "GlassEyes": The Theory of EyeTap Digital Eye Glass, supplemental material for IEEE Technology and Society, Volume Vol. 31, Number 3, 2012, pp. 10–14].</ref>) captures rays of light that would otherwise pass through the center of the lens of the wearer's eye, and substitutes synthetic computer-controlled light for each ray of real light.

An example of an AR glasses product is the Snap Spectacles.<ref name="p442">{{cite web | last=Stein | first=Scott | title=I Tried Snap's New Standalone AR Glasses, Which Do Mixed Reality, AI and Work Outdoors | website=CNET | date=2024-09-17 | url=https://www.cnet.com/tech/computing/i-tried-snaps-new-standalone-ar-glasses-which-do-mixed-reality-ai-and-work-outdoors/ | access-date=2025-04-21}}</ref>

===Handheld===
[[File:Wikitude.jpg|thumb|An augmented reality app on a smartphone using [[GPS]] and a [[compass#Solid state compasses|solid state compass]]]]
A handheld display employs a small display that fits in a user's hand. All handheld AR solutions to date opt for video passthrough. Initially handheld AR employed [[fiducial marker]]s,<ref>[http://researchguides.dartmouth.edu/content.php?pid=227212&sid=1891183 Marker vs Markerless AR] {{webarchive|url=https://web.archive.org/web/20130128175349/http://researchguides.dartmouth.edu/content.php?pid=227212&sid=1891183 |date=28 January 2013 }}, Dartmouth College Library.</ref> and later GPS units and MEMS sensors such as digital compasses and [[six degrees of freedom]] accelerometer–[[gyroscope]]. Today [[simultaneous localization and mapping]] (SLAM) markerless trackers such as PTAM (parallel tracking and mapping) are starting to come into use. Handheld display AR promises to be the first commercial success for AR technologies. The two main advantages of handheld AR are the portable nature of handheld devices and the ubiquitous nature of camera phones. The disadvantages are the physical constraints of the user having to hold the handheld device out in front of them at all times, as well as the distorting effect of classically wide-angled mobile phone cameras when compared to the real world as viewed through the eye.<ref>{{cite web |last=Feiner |first=Steve |title=Augmented reality: a long way off? |url=http://www.pocket-lint.com/news/38869/augmented-reality-interview-steve-feiner |work=AR Week |publisher=Pocket-lint |access-date=3 March 2011|date=3 March 2011}}</ref>

===Contact lenses===
Contact lenses that display AR imaging are in development. These [[bionic contact lens]]es might contain the elements for display embedded into the lens including integrated circuitry, LEDs and an antenna for wireless communication.

The first contact lens display was patented in 1999 by Steve Mann and was intended to work in combination with AR spectacles, but the project was abandoned,<ref>{{Cite web|title=Full Page Reload|url=https://spectrum.ieee.org/profile-innovega|website=IEEE Spectrum: Technology, Engineering, and Science News|date=10 April 2013|language=en|access-date=2020-05-06}}</ref><ref>{{Cite web|url=https://patents.google.com/patent/CA2280022/en|title=Contact lens for the display of information such as text, graphics, or pictures}}</ref> then 11 years later in 2010–2011.<ref>Greenemeier, Larry. [http://blogs.scientificamerican.com/observations/2011/11/23/computerized-contact-lenses-could-enable-in-eye-augmented-reality/ Computerized Contact Lenses Could Enable In-Eye Augmented Reality]. ''[[Scientific American]]'', 23 November 2011.</ref><ref>Yoneda, Yuka. [http://inhabitat.com/solar-powered-augmented-contact-lenses-cover-your-eye-with-100s-of-leds/ Solar Powered Augmented Contact Lenses Cover Your Eye with 100s of LEDs]. ''inhabitat'', 17 March 2010.</ref><ref>{{cite web |last=Rosen |first=Kenneth |title=Contact Lenses Can Display Your Text Messages |url=http://mashable.com/2012/12/08/contact-lenses-text-messages/|work=Mashable.com |date=8 December 2012 |access-date=13 December 2012}}</ref><ref>{{cite news|last=O'Neil |first=Lauren |title=LCD contact lenses could display text messages in your eye |url=http://www.cbc.ca/news/yourcommunity/2012/12/lcd-contact-lenses-could-display-text-messages-in-your-eye.html |publisher=[[CBC News]] |access-date=12 December 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121211075000/http://www.cbc.ca/news/yourcommunity/2012/12/lcd-contact-lenses-could-display-text-messages-in-your-eye.html |archive-date=11 December 2012 }}</ref> Another version of contact lenses, in development for the U.S. military, is designed to function with AR spectacles, allowing soldiers to focus on close-to-the-eye AR images on the spectacles and distant real world objects at the same time.<ref>Anthony, Sebastian. [http://www.extremetech.com/computing/126043-us-military-developing-multi-focus-augmented-reality-contact-lenses US military developing multi-focus augmented reality contact lenses]. ''[[ExtremeTech]]'', 13 April 2012.</ref><ref>Bernstein, Joseph. [http://www.popsci.com/diy/article/2012-05/2012-invention-awards-augmented-reality-contact-lenses 2012 Invention Awards: Augmented-Reality Contact Lenses] ''Popular Science'', 5 June 2012.</ref>

At CES 2013, a company called Innovega also unveiled similar contact lenses that required being combined with AR glasses to work.<ref>{{Cite web|title=Innovega combines glasses and contact lenses for an unusual take on augmented reality|url=https://www.theverge.com/2013/1/10/3863550/innovega-augmented-reality-glasses-contacts-hands-on|last=Robertson|first=Adi|date=2013-01-10|website=The Verge|language=en|access-date=2020-05-06}}</ref>

The first publicly unveiled working prototype of an AR contact lens not requiring the use of glasses in conjunction was developed by Mojo Vision and announced and shown off at CES 2020.<ref>{{Cite web|title=Full Page Reload|url=https://spectrum.ieee.org/ar-in-a-contact-lens-its-the-real-deal|website=IEEE Spectrum: Technology, Engineering, and Science News|date=16 January 2020|language=en|access-date=2020-05-06}}</ref><ref>{{Cite web|title=Mojo Vision's AR contact lenses are very cool, but many questions remain|url=https://techcrunch.com/2020/01/16/mojo-visions-ar-contact-lenses-are-very-cool-but-many-questions-remain/|website=TechCrunch|date=16 January 2020 |language=en-US|access-date=2020-05-06}}</ref><ref>{{Cite web|title=Mojo Vision is developing AR contact lenses|url=https://techcrunch.com/video/mojo-vision-is-developing-ar-contact-lenses/|website=TechCrunch|date=16 January 2020 |language=en-US|access-date=2020-05-06}}</ref>

===Virtual retinal display===
A [[virtual retinal display]] (VRD) is a type of theoretical display device that was in development at the [[University of Washington]]'s Human Interface Technology Laboratory under Dr. Thomas A. Furness III.<ref name="Viirre-1998">{{Cite journal|last1=Viirre|first1=E.|last2=Pryor|first2=H.|last3=Nagata|first3=S.|last4=Furness|first4=T. A.|date=1998|title=The virtual retinal display: a new technology for virtual reality and augmented vision in medicine|journal=Studies in Health Technology and Informatics|volume=50|issue=Medicine Meets virtual reality|pages=252–257|issn=0926-9630|pmid=10180549|doi=10.3233/978-1-60750-894-6-252}}</ref> With this technology, a display is scanned directly onto the [[retina]] of a viewer's eye. This results in bright images with high resolution and high contrast. The viewer sees what appears to be a conventional display floating in space.<ref>Tidwell, Michael; Johnson, Richard S.; Melville, David; Furness, Thomas A.[http://www.hitl.washington.edu/publications/p-95-1/ The Virtual Retinal Display – A Retinal Scanning Imaging System] {{webarchive|url=https://web.archive.org/web/20101213134809/http://www.hitl.washington.edu/publications/p-95-1/ |date=13 December 2010 }}, Human Interface Technology Laboratory, University of Washington.</ref>

Several of tests were done to analyze the safety of the VRD.<ref name="Viirre-1998" /> In one test, patients with partial loss of vision—having either [[macular degeneration]] (a disease that degenerates the retina) or [[keratoconus]]—were selected to view images using the technology. In the macular degeneration group, five out of eight subjects preferred the [https://immersivestudio.co.uk/services/virtual-reality-services/ VRD] images to the [[cathode-ray tube]] (CRT) or paper images and thought they were better and brighter and were able to see equal or better resolution levels. The Keratoconus patients could all resolve smaller lines in several line tests using the VRD as opposed to their own correction. They also found the VRD images to be easier to view and sharper. As a result of these several tests, virtual retinal display is considered safe technology.

Virtual retinal display creates images that can be seen in ambient daylight and ambient room light. The VRD is considered a preferred candidate to use in a surgical display due to its combination of high resolution and high contrast and brightness. Additional tests show high potential for VRD to be used as a display technology for patients that have low vision.

===Projection mapping===
[[Projection mapping]] augments real-world objects and scenes without the use of special displays such as monitors, head-mounted displays or hand-held devices. Projection mapping makes use of digital projectors to display graphical information onto physical objects. The key difference in projection mapping is that the display is separated from the users of the system. Since the displays are not associated with each user, projection mapping scales naturally up to groups of users, allowing for collocated collaboration between users.

Examples include [[shader lamps]], mobile projectors, virtual tables, and smart projectors. Shader lamps mimic and augment reality by projecting imagery onto neutral objects. This provides the opportunity to enhance the object's appearance with materials of a simple unit—a projector, camera, and sensor.

Other applications include table and wall projections. Virtual showcases, which employ beam splitter mirrors together with multiple graphics displays, provide an interactive means of simultaneously engaging with the virtual and the real.

A projection mapping system can display on any number of surfaces in an indoor setting at once. Projection mapping supports both a graphical visualization and passive [[Haptic perception|haptic]] sensation for the end users. Users are able to touch physical objects in a process that provides passive haptic sensation.<ref name="Azuma_survey" /><ref name="raskarSAR">Ramesh Raskar, Greg Welch, Henry Fuchs [https://web.archive.org/web/19981205111134/http://www.cs.unc.edu/~raskar/Office/ Spatially Augmented Reality], First International Workshop on Augmented Reality, Sept 1998.</ref><ref>Knight, Will. [https://www.newscientist.com/article/dn7695 Augmented reality brings maps to life] 19 July 2005.</ref><ref>Sung, Dan. [http://www.pocket-lint.com/news/38802/augmented-reality-maintenance-and-repair Augmented reality in action – maintenance and repair]. ''Pocket-lint'', 1 March 2011.</ref>