![Active-3d-shutter-technology](https://upload.wikimedia.org/wikipedia/commons/b/bb/Active-3d-shutter-technology.gif)
An active shutter 3D system (a.k.a. alternate frame sequencing, alternate image, AI, alternating field, field sequential or eclipse method) is a technique of displaying
stereoscopic 3D images. It works by only presenting the image intended for the left eye while blocking the right eye's view, then presenting the right-eye image while blocking the left eye, and repeating this so rapidly that the interruptions do not interfere with the perceived fusion of the two images into a single 3D image.
Modern active shutter 3D systems generally use liquid crystal shutter glasses (also called "LC shutter glasses" or "active shutter glasses"). Each eye's glass contains a
liquid crystal layer which has the property of becoming opaque when
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to ...
is applied, being otherwise
transparent
Transparency, transparence or transparent most often refer to:
* Transparency (optics), the physical property of allowing the transmission of light through a material
They may also refer to:
Literal uses
* Transparency (photography), a still, ...
. The glasses are controlled by a timing signal that allows the glasses to alternately block one eye, and then the other, in synchronization with the
refresh rate
The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate ...
of the screen. The timing synchronization to the video equipment may be achieved via a wired signal, or wirelessly by either an
infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
or
radio frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the ...
(e.g.
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
, DLP link) transmitter. Historic systems also used spinning discs, for example the
Teleview system.
Active shutter 3D systems are used to present
3D films in some theaters, and they can be used to present 3D images on
CRT,
plasma,
LCD, projectors and other types of video displays.
Advantages and disadvantages
Although virtually all ordinary unmodified video and computer systems can be used to display 3D by adding a plug-in interface and active shutter glasses, disturbing levels of flicker or ghosting may be apparent with systems or displays not designed for such use. The rate of alternation required to completely eliminate noticeable flicker depends on image brightness and other factors, but is typically well over 30 image pair cycles per second, the maximum possible with a 60 Hz display. A 120 Hz display, allowing 60 images per second per eye, is widely accepted as flicker-free.
Advantages
* Unlike
red/cyan color filter (anaglyph) 3D glasses, LC shutter glasses are color neutral, enabling 3D viewing in the full color spectrum, though the
ColorCode anaglyph system does come very close to providing full color resolution.
* Unlike in a
Polarized 3D system
A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye (an example of stereoscopy).
To present stereoscopic images and films, two images are projected s ...
, where the (usually) horizontal spatial resolution is halved, the active shutter system can retain full resolution (
1080p
1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen ve ...
) for both the left and right images. Like any system, manufacturers of televisions may choose not to implement the full resolution for 3D playback but use halved vertical resolution (540p) instead.
Disadvantages
* Flicker can be noticed except at very high refresh rates, as each eye is effectively receiving only half of the monitor's actual refresh rate. However, modern LC glasses generally work in higher refresh rates and eliminate this problem for most people.
* Until recently, the method only worked with
CRT monitors; some modern
flat-panel
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment.
Flat-panel displays are thin, lightweight, provide better l ...
monitors now support high-enough refresh rates to work with some LC shutter systems. Many projectors, especially DLP-based ones, support 3D out of the box.
* LC shutter glasses are shutting out light half of the time; moreover, they are slightly dark even when letting light through, because they are
polarized. This gives an effect similar to watching TV with sunglasses on, which causes a darker picture to be perceived by the viewer. However, this effect can produce a higher perceived
display contrast
Contrast in visual perception is a felt difference in appearance of two or more parts of a field seen simultaneously or successively (hence: brightness contrast, lightness contrast, color contrast, simultaneous contrast, successive contrast, etc.). ...
when paired with LCDs because of the reduction in
backlight bleed. Since the glasses also darken the background, contrast is enhanced when using a brighter image.
* When used with LCDs, extreme localized differences between the image to be displayed in one eye and the other may lead to
crosstalk, due to LCD panels' pixels sometimes being unable to fully switch, for example from black to white, in the time that separates the left eye's image from the right one. Recent advancements in the panel's response time, however, has led to displays that rival or even surpass passive 3D systems.
* Frame rate has to be double that of a non-3D, anaglyph, or
polarized 3D system
A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye (an example of stereoscopy).
To present stereoscopic images and films, two images are projected s ...
s to get an equivalent result. All equipment in the chain has to be able to process frames at double rate; in essence this doubles the hardware requirements.
* Despite a progressive fall in prices, due to the intrinsic use of electronics, they remain more expensive than anaglyph and polarized 3D glasses.
* Because of their integrated electronics and batteries, early shutter glasses were heavy and expensive. However, design improvements have resulted in newer models that are cheaper, lightweight, rechargeable and able to be worn over prescription lenses.
* From brand to brand, shutter glasses use different synchronization methods and protocols. Therefore, even glasses that use the same kind of synchronization system (e.g. infrared) will probably be incompatible across different makers. However, efforts are being made to create a universal 3D shutter glass.
* Alternated viewing of left and right views leads to an effect of time parallax, if there are side moving objects in the scene: they are seen as in front or behind their actual location, according to the move direction.
Crosstalk
Crosstalk is the leakage of frames between left eye and right eye. LCDs have exhibited this problem more often than plasma and DLP displays, due to slower
pixel response time
In technology, response time is the time a system or functional unit takes to react to a given input.
Computing
Response time is the total amount of time it takes to respond to a request for service. That service can be anything from a memory ...
. LCDs that utilize a strobe backlight, such as nVidia's LightBoost, reduce crosstalk. This is done by turning off the backlight between refreshes, while waiting for the shutter glasses to switch eyes, and also for the LCD panel to finish pixel transitions.
Standards
In March 2011
Panasonic Corporation
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb s ...
, together with
XPAND 3D, have formulated the
M-3DI Standard The M-3DI Standard, announced by Panasonic Corporation together with XpanD 3D in March 2011, aims to provide industry-wide compatibility and standardisation of LC (Active) Shutter Glasses hardware between manufacturers.
This movement aims to brin ...
, which aims to provide industry-wide compatibility and standardization of LC Shutter Glasses. This movement aims to bring about compatibility among manufacturers of 3D TV, computer, notebook, home projection, and cinema with standardized LC shutter glasses that will work across all 3D hardware seamlessly. The current standard is Full HD 3D Glasses.
Field Sequential has been used in video games, VHS and VHD movies and is often referred to as HQFS for DVDs, these systems use wired or wireless LCS glasses.
The Sensio format was used with DVDs using wireless LCS glasses.
Each different active 3D shutter glasses implementation can operate in their own manufacturer-set
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
to match the refresh rate of the display or projector. Therefore, to achieve compatibility across different brands, certain glasses have been developed to be able to adjust to a broad range of frequencies.
Timeline
The principle made its public debut remarkably early. In 1922, the
Teleview 3-D system was installed in a single theater in New York City. Several short films and one feature-length film were shown by running left-eye and right-eye prints in a pair of interlocked projectors with their shutters operating out of phase. Each seat in the auditorium was equipped with a viewing device containing a rapidly rotating mechanical shutter synchronized with the projector shutters. The system worked, but the expense of the installation and the unwieldiness of the viewers, which had to be supported on adjustable stands, confined its use to this one engagement.
In recent decades, the availability of lightweight optoelectronic shutters has led to an updated revival of this display method. Liquid crystal shutter glasses were first invented by Stephen McAllister of
Evans and Sutherland Computer Corporation in the mid-1970s. The prototype had the LCDs mounted to a small cardboard box using duct tape. The glasses were never commercialized due to
ghosting, but E&S was a very early adopter of third-party glasses such as the
StereoGraphics CrystalEyes
Leonard Lipton (May 18, 1940 – October 5, 2022) was an American author, filmmaker, lyricist and inventor. At age 19, Lipton wrote the poem that became the basis for the lyrics to the song "Puff, the Magic Dragon". He went on to write books on ...
in the mid-1980s.
Matsushita Electric (now Panasonic) developed a
3D television that employed active-shutter technology in the late 1970s. They unveiled the television in 1981, while at the same time adapting the technology for use with the first
stereoscopic video game,
Sega's arcade game ''
SubRoc-3D'' (1982).
In 1985 3D
VHD players became available in Japan from manufacturers such as Victor (
JVC),
National
National may refer to:
Common uses
* Nation or country
** Nationality – a ''national'' is a person who is subject to a nation, regardless of whether the person has full rights as a citizen
Places in the United States
* National, Maryland, c ...
(
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...
), and
Sharp
Sharp or SHARP may refer to:
Acronyms
* SHARP (helmet ratings) (Safety Helmet Assessment and Rating Programme), a British motorcycle helmet safety rating scheme
* Self Help Addiction Recovery Program, a charitable organisation founded in 19 ...
. Other units were available for field sequential VHS tapes including the Realeyes 3D. A few kits were made available to watch field sequential DVDs. Sensio released their own format which was higher quality than the High Quality Field Sequential (HQFS) DVDs.
Games
![Famicom-3D-System](https://upload.wikimedia.org/wikipedia/commons/2/20/Famicom-3D-System.jpg)
The method of alternating frames can be used to render modern 3D games into
true 3D
3D computer graphics, or “3D graphics,” sometimes called CGI, 3D-CGI or three-dimensional computer graphics are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for th ...
, although a similar method involving alternate fields has been used to give a 3D illusion on consoles as old as the
Master System and
Family Computer
The Nintendo Entertainment System (NES) is an 8-bit Third generation of video game consoles, third-generation home video game console produced by Nintendo. It was first released in Japan in 1983 as the commonly known as the The NES, a redes ...
. Special software or hardware is used generate two channels of images, offset from each other to create the stereoscopic effect. High frame rates (typically ~100fps) are required to produce seamless graphics, as the perceived frame rate will be half the actual rate (each eye sees only half the total number of frames). Again, LCD shutter glasses synchronized with the graphics chip complete the effect.
In 1982,
Sega's
arcade
Arcade most often refers to:
* Arcade game, a coin-operated game machine
** Arcade cabinet, housing which holds an arcade game's hardware
** Arcade system board, a standardized printed circuit board
* Amusement arcade, a place with arcade games
* ...
video game ''
SubRoc-3D'' came with a special 3D eyepiece,
which was a viewer with spinning discs to alternate left and right images to the player's eye from a single monitor.
[Bernard Perron & Mark J. P. Wolf (2008), ''Video game theory reader two'']
p. 158
Taylor & Francis
Taylor & Francis Group is an international company originating in England that publishes books and academic journals. Its parts include Taylor & Francis, Routledge, F1000 (publisher), F1000 Research or Dovepress. It is a division of Informa ...
, The game's active shutter 3D system was jointly developed by Sega with
Matsushita (now Panasonic).
In 1984,
Milton Bradley
Milton Bradley (November 8, 1836 – May 30, 1911) was an American business magnate, game pioneer and publisher, credited by many with launching the board game industry, with his eponymous enterprise, which was purchased by Hasbro in 1984, and ...
released the 3D Imager, a primitive form of active shutter glasses that used a motorized rotating disc with transparencies as physical shutters, for the
Vectrex
The Vectrex is a vector display-based home video game console–the only one ever designed and released for the home market, developed by Smith Engineering. It was first released for the North America market in November 1982 and then Europe an ...
. Although bulky and crude, they used the same basic principle of rapidly alternating imagery that modern active shutter glasses still use.
Nintendo released the
Famicom 3D System
The Famicom 3D System is a Japan-exclusive accessory for the Nintendo Family Computer releasedPlunkett, Luke. Nintendo's First 3D Technology Shot A Spaceship At Mario's Face'. Kotaku. 30 April 2010. in 1987.
Overview
The 3D System consists of ...
for the
Famicom
The Nintendo Entertainment System (NES) is an 8-bit Third generation of video game consoles, third-generation home video game console produced by Nintendo. It was first released in Japan in 1983 as the commonly known as the The NES, a redes ...
in October 1987 in Japan, which was an LCD shutter headset, the first home video game electronic device to use LCD Active Shutter glasses. Sega released the
SegaScope 3-D for the
Master System Worldwide in November 1987. Only eight 3D compatible games were ever released.
In 1993
Pioneer
Pioneer commonly refers to a settler who migrates to previously uninhabited or sparsely inhabited land.
In the United States pioneer commonly refers to an American pioneer, a person in American history who migrated west to join in settling and de ...
released the
LaserActive
The is a converged device and fourth-generation home video game console capable of playing LaserDiscs, Compact Discs, console games, and LD-G karaoke discs. It was released by Pioneer Corporation in 1993. In addition to LaserActive games, separa ...
system which had a bay for various "PAC's" such as the Mega LD PAC and LD-ROM² PAC. The unit was 3D capable with the addition of the LaserActive 3D goggles (GOL-1) and the adapter (ADP-1).
While the 3D hardware for these earlier video game systems is almost entirely in the hands of collectors it is still possible to play the games in 3D using emulators, for example using a Sega Dreamcast with a Sega Master System emulator in conjunction with a CRT television and a 3D system like the one found in The Ultimate 3-D Collection.
In 1999–2000, a number of companies created stereoscopic LC shutter glasses kits for the
Windows PCs which worked with application and games written for
Direct3D and
OpenGL 3D graphics
3D computer graphics, or “3D graphics,” sometimes called CGI, 3D-CGI or three-dimensional computer graphics are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for th ...
API
An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...
s. These kits only worked with CRT computer displays and employed either
VGA pass-through,
VESA Stereo
VESA Stereo is a liquid crystal shutter glasses interface standard by the Video Electronics Standards Association (VESA) for stereoscopic
Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing ...
or proprietary interface for left–right synchronization.
The most prominent example was the ELSA Revelator glasses, which worked exclusively in Nvidia cards through a proprietary interface based on VESA Stereo. Nvidia later bought the technology and used it in its
stereo driver for Windows.
The glasses kits came with driver software which intercepted API calls and effectively rendering the two views in sequence; this technique required twice the performance from the
graphic card
A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer mo ...
, so a high-end device was needed. Visual glitches were common, as many 3D
game engines relied on 2D effects which were rendered at the incorrect depth, causing disorientation for the viewer. Very few CRT displays were able to support a 120 Hz
refresh rate
The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate ...
at common gaming resolutions of the time, so high-end CRT display was required for a flicker-free image; and even with a capable CRT monitor, many users reported flickering and headaches.
These CRT kits were entirely incompatible with common LCD monitors which had very high
pixel response time
In technology, response time is the time a system or functional unit takes to react to a given input.
Computing
Response time is the total amount of time it takes to respond to a request for service. That service can be anything from a memory ...
s, unlike CRT displays. Moreover, the display market swiftly shifted to LCD monitors and most display makers ceased production of CRT monitors in early 2000s, which meant that PC glasses kits shortly fell into disuse and were reduced to a very niche market, requiring a purchase of a used high-end, big diagonal CRT monitor.
SplitFish EyeFX 3D was a stereo 3D shutter glasses kit for the Sony
PlayStation 2 released in 2005; it only supported standard-definition CRT TVs. The accessory included a pass-through cable for the PS2 gamepad; when activated, the attached accessory would issue a sequence of rapidly alternating left–right movement commands to the console, producing a kind of "
wiggle stereoscopy
Wiggle stereoscopy is an example of stereoscopy in which left and right images of a stereogram are animated. This technique is also called wiggle 3-D, wobble 3-D, or sometimes Piku-Piku (Japanese for "twitching").
The sense of depth from such i ...
" effect additionally aided by the wired LC shutter glasses which worked in sync with these movements. The kit arrived too late in the product cycle of the console when it was effectively replaced by the
PlayStation 3
The PlayStation 3 (PS3) is a home video game console developed by Sony Computer Entertainment. The successor to the PlayStation 2, it is part of the PlayStation brand of consoles. It was first released on November 11, 2006, in Japan, November ...
, and only a few games were supported, so it was largely ignored by gamers.
The USB-based
Nvidia 3D Vision
Nvidia 3D Vision (previously ''GeForce 3D Vision'') is a discontinued stereoscopic gaming kit from Nvidia which consists of LC shutter glasses and driver software which enables stereoscopic vision for any Direct3D game, with various degrees of co ...
kit released in 2008 supports CRT monitors capable of 100, 110, or 120 Hz refresh rates, as well as 120 Hz LCD monitors.
Hardware
Active shutter 3D system providers
There are many sources of low-cost 3D glasses. IO glasses are the most common glasses in this category.
XpanD 3D is a manufacturer of shutter glasses, with over 1000 cinemas currently using XpanD glasses. With the release of this technology to the home-viewer market as of 2009, many other manufacturers are now developing their own LC shutter glasses, such as Unipolar International Limited, Accupix Co., Ltd,
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...
,
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
, and
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
.
The
M-3DI Standard The M-3DI Standard, announced by Panasonic Corporation together with XpanD 3D in March 2011, aims to provide industry-wide compatibility and standardisation of LC (Active) Shutter Glasses hardware between manufacturers.
This movement aims to brin ...
, announced by
Panasonic Corporation
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb s ...
together with
XPAND 3D in March 2011, aims to provide industry-wide compatibility and standardization of
LC (Active) Shutter Glasses.
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
has developed active 3D glasses that are and utilize lens and frame technology pioneered by
Silhouette
A silhouette ( , ) is the image of a person, animal, object or scene represented as a solid shape of a single colour, usually black, with its edges matching the outline of the subject. The interior of a silhouette is featureless, and the silhou ...
, who creates glasses for
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
.
Nvidia
Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as VIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as VIDIA with a large italicized lowercase "n" on products from the mid 1990s to ...
makes a
3D Vision kit for the PC; it comes with 3D shutter glasses, a transmitter, and special graphics driver software. While regular LCD monitors run at 60 Hz, a 120 Hz monitor is required to use 3D Vision.
Other well known providers of active 3D glasses include EStar America and Optoma. Both companies produce 3D Glasses compatible with a variety of technologies, including RF, DLP Link and Bluetooth.
DLP 3D
In 2007, Texas Instruments introduced stereo 3D capable
DLP solutions to its OEMs, Samsung and Mitsubishi then introduced the first 3D ready DLP televisions, and DLP 3D projectors came later.
These solutions utilize the inherent speed advantage of the Digital Micro-mirror Device (DMD) to sequentially generate a high refresh rate for the left and right views required for stereoscopic imaging.
DLP 3D technology uses the SmoothPicture
wobulation algorithm and relies on the properties of modern 1080p60 DMD imagers. It effectively compacts two L/R views into a single frame by using a
checkerboard pattern, only requiring a standard 1080p60 resolution for stereoscopic transmission to the TV. The claimed advantage of this solution is increased spatial resolution, unlike other methods which cut vertical or horizontal resolution in half.
The micromirrors are organized in a so-called "offset-diamond pixel layout" of 960×1080 micromirrors, rotated 45 degrees, with their center points placed in the center of "black" squares on the checkerboard. The DMD employs full-pixel
wobulation to display the complete 1080p image as two half-resolution images in a fast sequence. The DMD operates at twice the refresh rate, i.e. 120 Hz, and the complete 1080p picture is displayed in two steps. On the first cadence, only half of the original 1080p60 image is displayed – the pixels that correspond to the "black" squares of the checkerboard pattern. On the second cadence, the DMD array is mechanically shifted ("wobulated") by one pixel, so the micromirrors are now in a position previously occupied by the gaps, and another half of the image is displayed – this time, the pixels that correspond to the "white" squares.
A synchronization signal is then generated to synchronize the screen's refresh with LC shutter glasses worn by the viewer, using Texas Instruments' proprietary mechanism called DLP Link.
DLP Link keeps sync by embedding briefly-flashed white frames during the display's
blanking interval
In analog video, blanking occurs between horizontal lines and between frames. In raster scan equipment, an image is built up by scanning an electron beam from left to right across a screen to produce a visible trace of one scan line, reducing the ...
, which are picked up by the LC shutter glasses.
Plasma TV
Plasma display panel
A plasma display panel (PDP) is a type of flat panel display that uses small cells containing plasma: ionized gas that responds to electric fields. Plasma televisions were the first large (over 32 inches diagonal) flat panel displays to be release ...
s are inherently high-speed devices as well, since they use
pulse-width modulation to maintain the brightness of individual pixels, making them compatible with sequential method involving shutter glasses. Modern panels feature pixel driving frequency of up to 600 Hz and allow 10-bit to 12-bit color precision with 1024 to 4096 gradations of brightness for each subpixel.
Samsung Electronics launched 3D ready PDP TVs in 2008, a "PAVV Cannes 450" in Korea and PNAx450 in the UK and the US. The sets utilize the same checkerboard pattern compression scheme as their DLP TVs, though only at the native resolution of 1360×768 pixels and not at HDTV standard 720p, making them only usable with a PC.
Matsushita Electric (Panasonic) prototyped the "3D Full-HD Plasma Theater System" on CES 2008. The system is a combination of a 103-inch
PDP TV, a Blu-ray Disc player and
shutter glasses
An active shutter 3D system (a.k.a. alternate frame sequencing, alternate image, AI, alternating field, field sequential or eclipse method) is a technique of displaying stereoscopic 3D images. It works by only presenting the image intended for th ...
. The new system transmits 1080i60 interlaced images for both right and left eyes, and the video is stored on 50-gigabyte Blu-ray using the MPEG-4 AVC/H.264 compression
Multiview Video Coding
Multi view Video Coding (MVC, also known as MVC 3D) is a stereoscopic video coding standard for video compression that allows for the efficient encoding of video sequences captured simultaneously from multiple camera angles in a single video str ...
extension.
LCD
Formerly, LCDs were not very suitable for stereoscopic 3D due to slow
pixel response time
In technology, response time is the time a system or functional unit takes to react to a given input.
Computing
Response time is the total amount of time it takes to respond to a request for service. That service can be anything from a memory ...
. Liquid crystal displays have traditionally been slow to change from one polarization state to another. Users of early 1990s laptops are familiar with the smearing and blurring that occurs when something moves too fast for the LCD to keep up.
LCD technology is not usually rated by frames per second but rather the time it takes to transition from one pixel color value to another pixel color value. Normally, a 120 Hz refresh is displayed for a full 1/120 second (8.33 milliseconds) due to
sample-and-hold
In electronics, a sample and hold (also known as sample and follow) circuit is an analog device that samples (captures, takes) the voltage of a continuously varying analog signal and holds (locks, freezes) its value at a constant level for a ...
, regardless of how quickly an LCD can complete pixel transitions. Recently, it became possible to hide pixel transitions from being seen, using strobe backlight technology, by turning off the backlight between refreshes,
AnandTech article, mentioning the LightBoost strobe backlight technique
/ref> to reduce crosstalk. Newer LCD televisions, including high end Sony and Samsung 3D TVs, now utilize a strobed backlight
Display motion blur, also called ''HDTV blur'' and ''LCD motion blur'', refers to several visual artifacts (anomalies or unintended effects affecting still or moving images) that are frequently found on modern consumer high-definition television se ...
or scanning backlight to reduce 3D crosstalk during shutter glasses operation.
Therapeutic alternating occlusion
In vision therapy
Vision therapy (VT), or behavioral optometry, is an umbrella term for alternative medicine treatments using eye exercises, based around the pseudoscientific claim that vision problems are the true underlying cause of learning disabilities, parti ...
of amblyopia and of intermittent central suppression
Suppression may refer to:
Laws
* Suppression of Communism Act
*Suppression order a type of censorship where a court rules that certain information cannot be published
* Tohunga Suppression Act 1907, an Act of the Parliament of New Zealand aimed ...
, liquid crystal devices have been used for purposes of enhanced occlusion therapy. In this scenario, the amblyopic patient wears electronically programmable liquid crystal glasses or goggles for continuously for several hours during regular everyday activities. Wearing the device encourages or forces the patient to use both eyes alternatingly, similar to eye patch
An eyepatch is a small patch that is worn in front of one eye. It may be a cloth patch attached around the head by an elastic band or by a string, an adhesive bandage, or a plastic device which is clipped to a pair of glasses. It is often worn ...
ing, but rapidly alternating in time. The aim is to circumvent the patient's tendency to suppress the field of view of the weaker eye and to train the patient's capacity for binocular vision
In biology, binocular vision is a type of vision in which an animal has two eyes capable of facing the same direction to perceive a single three-dimensional image of its surroundings. Binocular vision does not typically refer to vision where an ...
. The goggles mostly feature a much slower flicker rate than the more well-known active shutter 3D glasses.
See also
* 3D television
*Digital 3D
Digital 3D is a non-specific 3D standard in which films, television shows, and video games are presented and shot in digital 3D technology or later processed in digital post-production to add a 3D effect.
One of the first studios to use digital 3 ...
* Teleview
* LED TV
*CrystalEyes
Leonard Lipton (May 18, 1940 – October 5, 2022) was an American author, filmmaker, lyricist and inventor. At age 19, Lipton wrote the poem that became the basis for the lyrics to the song "Puff, the Magic Dragon". He went on to write books on ...
References
External links
Panasonic.com/3d
– Overview of Technology of 3D Cinema and LC Shutter Glasses
3D Vision reviewed
– Nvidia's 3D Vision explained and reviewed
{{Eyewear
Stereoscopy
Liquid crystal displays
3D imaging
Eyewear