Head-mounted display
A head-mounted display (HMD) is an electronic visual display that is worn on the head and can be used for 3D electronic interaction. It is fixed in place to a user's head or eyes. It may have a large or small field of view. It may or may not have 3D tracking capability. It has one or more near-eye display modules or is made as an integrated system.
Head-mounted displays can use see-through or opaque near-eye display modules.
An HMD may connect to an external computer for display output and optional 3D tracking.
Large-field of view headsets are used in virtual reality (VR). Head-mounted displays were part of the second wave of successful VR headsets such as the Oculus Rift.
The most popular type is a binocular head-mounted display, with one small display for each eye. However, zograscopes beat fixed-focus binocular stereoscopic head-mounted displays in 3DEI performance.
An HMD is largely useful if it shows visual content to a large portion of both eyes.
As computers have become more power efficient, head-worn computers have in most cases replaced head-mounted displays.
The outer shell of the headset shares a coordinate system with the user's head.
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.
One of the first head-mounted displays was Headsight in 1961.
The first HMD connected to a computer for 3D rendering was the Sutherland head-mounted display.
Displays that are binocular but display the same image to both eyes suffer from non-linear binocular artifacts that the human brain did not evolve to develop. This causes visual system strain. It is due to imperfections in the optics of the display system giving slightly different images to both eyes that are different from natural binocular disparity, such as shearing. This is not a problem if using a monoscopic head-mounted display.
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.
Virtual reality (periphery blocked)[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]
History[edit]
Head-mounted displays have often been used for military and aerospace applications.
Bell Helicopter[edit]
In 1963, Bell Helicopter company in Fort Worth, Texas, experimented with a pilot-controlled night vision system. There was a camera controlled by servo motors. The servo-controlled camera system used a headset displaying a night-vision view of the ground for the pilot via an infrared camera mounted under the helicopter. The head-mounted display was similar to the Headsight system.[4]
References[edit]
- ↑ https://web.archive.org/web/20120206062431/https://www.leepvr.com/cyberface1.php Accessed May 1, 2024
- ↑ 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.
- ↑ Jon, Peddie (2017). Augmented reality: where we will all live. Cham, Switzerland. pp. 65. ISBN 9783319545028. OCLC 983466007.