Jump to content

Head-mounted display: Difference between revisions

From VR & AR Wiki
← Older edit
VisualWikitext
Neo222 (talk | contribs)
Bots
15,794 edits
RealEditor (talk | contribs)
239 edits
No edit summary
 
(52 intermediate revisions by 5 users not shown)
Line 1: Line 1:
{{stub}}
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]].
'''Head-mounted display''' or '''HMD''' is a [[device]] worn over your head. It features a display in front of one or both of your eyes. The display streams data, images and other information in front of the wearer's eye(s). Certain HMDs such as [[Oculus Rift]] or [[HTC Vive]] have displays over both of their users' eyes. Others like [[Google Glass]] only have a display over one of the users' eyes.


The majority of [[Virtual Reality]] (VR) and [[Augmented Reality]] (AR) devices are head-mounted displays. In AR, the display is usually transparent and digital information is superimposed onto real life objects. These HMDs are called [[Optical head-mounted display]]s or [[OHMD]]s. In VR, the display is not transparent and only virtual information and images are displayed in front of wearer's eyes.
It uses two [[near-eye display]]s. Head-mounted displays can use see-through or opaque near-eye display modules.


==Virtual Reality HMDs==
It may connect to an external computer for display output and optional 3D tracking.
{{see also|Virtual Reality Devices}}
Head movement → Tracker → CPU → GPU → Display → Photons → Optics → Eyes
===Features===
====Large Field of View====
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.


====Stereoscopic 3D Imagery====
The outer shell of the headset shares a coordinate system with the user's head.
The HMD has to create the illusion of a 3D world. To accomplish this, the display shows both of our eyes two different images 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.


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


Rotational Tracking is achieved through sensors such as the [[Gyroscope]], [[Accelerometer]] and [[Magnetometer]] within the HMD.
Head-mounted displays were part of the second wave of commercially successful [[VR headset]]s such as the [[Oculus Rift]].


====Positional Tracking====
As computers have become more power efficient, [[head-worn computer]]s have in most cases replaced head-mounted displays.
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.


HMDs in the future will be able to track translational motion and perform positional tracking.
An HMD is largely useful if it shows visual content to a large portion of both eyes.


==Augmented Reality HMDs==
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.
{{main|Optical head-mounted display}}
Augmented Reality HMDs also known as Optical head-mounted displays or OHMDs. The displays of these devices are transparent. They allow users to see through them while projecting images and information in front of the users' eyes.


==Types of HMDs==
The first was part of [[Ivan Sutherland's head-mounted three dimensional display]] project.
[[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.  
__NOTOC__
===Slide-on HMD===
==Augmented reality HMDs==
[[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.
Augmented reality HMDs are also known as [[AR headset]]s. They are either [[optical see through]] or [[video passthrough]] devices.


Popular Slide-on HMDs:
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.
*[[Google Cardboard]]
*[[Samsung Gear VR]]


===Discrete HMD===
==VR==
[[Discrete HMD]] contains
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.


===Integrated HMD===
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"/>
[[Integrated HMD]]


==References==
{{Reflist}}


 
[[Category:Head-mounted display]]
[[Category:Terms]]

Latest revision as of 03:40, 11 July 2025

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

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

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

  1. ↑ https://web.archive.org/web/20120206062431/https://www.leepvr.com/cyberface1.php Accessed May 1, 2024
  2. ↑ 2.0 2.1 "LeepVR". 1996-03-27. http://www.leepvr.com/orbiter.php.
  3. ↑ "Visual Displays Frequently Asked Questions (FAQ)". 1997-07-19. https://users.ncsa.illinois.edu/tcoffin/vrdisplays.txt.
Retrieved from "https://vrarwiki.com/index.php?title=Head-mounted_display&oldid=36260"