Difference between revisions of "Head-mounted display"

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[[File:Oculus-Rift-CV1-Headset-Front.jpeg|thumb|right|250px|A head-mounted display]]
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[[File:Oculus Rift DK2.jpeg|thumb|An Oculus Rift Development Kit 2 headset]]
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A '''head-mounted display''' (HMD) is a display that is fixed to a user's head. It shares a coordinate system with the user's head. It is either monocular or binocular. It is also known as a head-fixed display. A common use is a [[VR headset]].
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A '''head-mounted display''' is an electronic visual display that is worn on the head. It is fixed in place to a user's head or eyes. It may have a large or small field of view. Large field of view headsets are used in [[virtual reality]].
  
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An HMD is largely useful if it is [[binocular]], and as such, shows two images, one for each eye. Other HMDs like the [[Google Glass]] only have a small display over one eye that is partially transparent.
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It uses two [[near-eye display]]s. Head-mounted displays can use see-through or opaque near-eye display modules.
  
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The majority of [[virtual reality]] (VR) and [[augmented reality]] (AR) devices are head-mounted displays. In VR, the display is not transparent and only virtual information and images are displayed in front of wearer's eyes. In AR, the display is usually transparent and digital information is superimposed onto real life objects. These HMDs are called optical see through head mounted displays (OST-HMD). [[Video passthrough]] can also be done.
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It may connect to an external computer for display output and optional 3D tracking.
  
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A display is placed very close to the users' eyes, covering a large portion of their field of view. Most headsets are flat focus binocular, meaning two images that are very similar but have different perspectives are channeled into the eyes, one for the left and one for the right, to allow the human perceptual system to perceive [[binocular disparity]] and see some depth.
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The outer shell of the headset shares a coordinate system with the user's head.
  
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VR headsets with flat focus have lenses that are placed between the display and the user's eyes. The lenses allow our eyes to focus on the images on the display, even though the display is only a few inches in front of our faces. Without lenses, our entire VR world would become blurry because human eyes have trouble focusing on things that are very close.<ref>http://doc-ok.org/?p=1360</ref>
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It is [[two-view]]. A head-mounted display is a [[head-fixed display]] that rests its mass on the user's head.
  
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==Virtual reality==
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Head-mounted displays were part of the second wave of commercially successful [[VR headset]]s such as the [[Oculus Rift]].
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VR headsets input head movement, which is taken in by a tracking system, fed to a [[CPU]], then a scene is rendered according to the head position by a [[GPU]], which is sent to a display system, which converts electrical signals to photons (light). Then the light optionally passes through optics and into the user's eyes.
 
  
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===Features===
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As computers have become more power efficient, [[head-worn computer]]s have in most cases replaced head-mounted displays.
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====Large Field of View====
 
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VR HMDs have displays with large [[field of view]] (FOV) that comprise the entirety of the user's vision. With both eyes, humans have about 180 degrees FOV when looking in front of them. The display of a VR device should cover as much of the vision range as possible. A large FOV is important to create [[immersion]] for the wearer.
 
  
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====Binocular stereoscopic imagery====
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An HMD is largely useful if it shows visual content to a large portion of both eyes.
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A VR HMD has to create the illusion of a 3D world. To accomplish this, the display shows each eye a different image of the same scene. The images are of the same scene viewed from slightly different angles. This process creates depth perception by mimicking how our eyes perceive the world in real life. It is called [[binocular disparity]].
 
  
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====Rotational Tracking====
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A display is placed very close to the users' eyes, covering a large portion of their field of view. Most headsets are flat focus binocular, meaning two images that are very similar but have different perspectives are channeled into the eyes, one for the left and one for the right, to allow the human perceptual system to perceive [[binocular disparity]] and see some depth.
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A key feature of an HMD is the ability to track the wearer's head rotations. The images shown on the display change according to the wearer's head movements. Head-tracking is an essential aspect of the HMD that allows the user to become immersed and feel [[presence]].
 
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Rotational Tracking is achieved through sensors such as the [[Gyroscope]], [[Accelerometer]] and [[Magnetometer]] within the HMD.
 
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====Positional Tracking====
 
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Positional Tracking is often performed with sensors and cameras external to the HMD. These peripherals can track the position of the user's head, body and hands anywhere within the range of the devices. They can not only track the rotational movements like the inboard sensors but also translational movements.
 
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HMDs in the future will be able to track translational motion and perform positional tracking.
 
  
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The first was part of [[Ivan Sutherland's head-mounted three dimensional display]] project.
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__NOTOC__
 
==Augmented reality HMDs==
 
==Augmented reality HMDs==
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Augmented reality HMDs are either optical see through devices or [[video passthrough]] devices.
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Augmented reality HMDs are also known as [[AR headset]]s. They are either [[optical see through]] or [[video passthrough]] devices.
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In an optical see through device, the displays of these devices are transparent. They allow users to see through them while projecting images and information.
 
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==Types==
 
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[[Slide-on HMD]] is the most primitive of all HMD types. These devices rely on the inserted smartphones to do all of the leg work. [[Discrete HMD]] contains a display and some electronics for [[tracking]] and other functions. While they are more advanced than the Slide-ons, Discrete HMDs still require connections to PCs for processing. [[Integrated HMD]] is the most sophisticated of them all. From display to tracking to processing, it has everything needed for VR or [[AR]] within the HMD.
 
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===Slide-on HMD===
 
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[[Slide-on HMD]], also known as Smartphone mount, is the cheapest and most accessible form of [[VR]]. The Slide-on consists of a smartphone holder, [[lenses]] and some form of basic [[input]]. A smartphone is inserted into the HMD and the entire device is played upon the eyes of the user to create the VR experience. The Slide-on utilizes the smartphone for display, processing and [[rotational tracking]]. Some Slide-on HMDs such as the [[Gear VR]] use their own built-in [[IMUs]] instead of relying on that of the smartphones.
 
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Popular Slide-on HMDs:
 
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*[[Google Cardboard]]
 
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*[[Samsung Gear VR]]
 
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===Discrete HMD===
 
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[[Discrete HMD]] also known as Tethered HMD supplies everything required for an [[immersive]] [[VR]] experience aside from the processing. It contains display, lenses, rotational tracking, [[positional tracking]], audio and advanced input. For processing, Discrete HMDs are connected to PCs through cables. While this type of HMD is less mobile than its 2 counter parts, it is able to deliver the best VR experience.
 
  
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Popular Discrete HMDs:
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In an optical see through device, the displays of these gadgets are transparent. They allow users to see through them while projecting images and information.
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*[[Oculus Rift]]
 
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*[[HTC Vive]]
 
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*[[PlayStation VR]]
 
  
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New
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==VR==
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*[[HTC Vive Pro]]
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The '''LEEP Cyberface''' is a commercial [[VR headset]]. It has [[flat focus]]. It was the first VR headset released commercially. It is monochromatic, and has a very high horizontal field of view.<ref>https://web.archive.org/web/20120206062431/https://www.leepvr.com/cyberface1.php Accessed May 1, 2024</ref> The Cyberface originally came packaged with a complete telepresence system.
  
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===Integrated HMD===
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The '''Cyberface4''' is a [[head-mounted display]] from [[LEEP Systems]].<ref name="l884">{{cite web | title=LeepVR | website=LeepVR | date=1996-03-27 | url=http://www.leepvr.com/orbiter.php | access-date=2024-09-09}}</ref> It has a single LCD panel.<ref name="m467">{{cite web | title=Visual Displays Frequently Asked Questions (FAQ) | website=NCSA | date=1997-07-19 | url=https://users.ncsa.illinois.edu/tcoffin/vrdisplays.txt | access-date=2024-09-09}}</ref> It is an upgraded version of the [[Cyberface3]].<ref name="l884"/>
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A standalone HMD, also known as an [[Integrated HMD]], is the most sophisticated and expensive type of HMD. This independent computing device is able to deliver [[VR]] and/or [[AR]] experiences without any external hardware such as PC or smartphone. It contains everything from display to processors to camera and is able to display stereoscopic 3D images, perform complex tracking and utilize advanced input methods. Examples are the [[Meta Quest Pro]] and the [[Meta Quest 3]].
 
  
 
==References==
 
==References==

Latest revision as of 15:53, 14 March 2025

An Oculus Rift Development Kit 2 headset

A head-mounted display is an electronic visual display that is worn on the head. It is fixed in place to a user's head or eyes. It may have a large or small field of view. Large field of view headsets are used in virtual reality.

It uses two near-eye displays. Head-mounted displays can use see-through or opaque near-eye display modules.

It may connect to an external computer for display output and optional 3D tracking.

The outer shell of the headset shares a coordinate system with the user's head.

It is two-view. A head-mounted display is a head-fixed display that rests its mass on the user's head.

Head-mounted displays were part of the second wave of commercially successful VR headsets such as the Oculus Rift.

As computers have become more power efficient, head-worn computers have in most cases replaced head-mounted displays.

An HMD is largely useful if it shows visual content to a large portion of both eyes.

A display is placed very close to the users' eyes, covering a large portion of their field of view. Most headsets are flat focus binocular, meaning two images that are very similar but have different perspectives are channeled into the eyes, one for the left and one for the right, to allow the human perceptual system to perceive binocular disparity and see some depth.

The first was part of Ivan Sutherland's head-mounted three dimensional display project.

Augmented reality HMDs[edit]

Augmented reality HMDs are also known as AR headsets. They are either optical see through or video passthrough devices.

In an optical see through device, the displays of these gadgets are transparent. They allow users to see through them while projecting images and information.

VR[edit]

The LEEP Cyberface is a commercial VR headset. It has flat focus. It was the first VR headset released commercially. It is monochromatic, and has a very high horizontal field of view.[1] The Cyberface originally came packaged with a complete telepresence system.

The Cyberface4 is a head-mounted display from LEEP Systems.[2] It has a single LCD panel.[3] It is an upgraded version of the Cyberface3.[2]

References[edit]

  • ↑ https://web.archive.org/web/20120206062431/https://www.leepvr.com/cyberface1.php Accessed May 1, 2024
  • ↑ Jump up to: 2.0 2.1 "LeepVR". 1996-03-27. http://www.leepvr.com/orbiter.php.
  • ↑ "Visual Displays Frequently Asked Questions (FAQ)". 1997-07-19. https://users.ncsa.illinois.edu/tcoffin/vrdisplays.txt.
    • Retrieved from "http://www.xvrwiki.org/index.php?title=Head-mounted_display&oldid=176217"