A holographic screen is a two-dimensional display technology that uses coated glass media for the projection surface of a

video projector A video projector is an image projector that receives a video signal and projects the corresponding image onto a projection screen using a lens system. Video projectors use a very bright ultra-high-performance lamp (a special mercury arc l ...

. "

Holographic Holography is a technique that allows a wavefront to be recorded and later reconstructed. It is best known as a method of generating three-dimensional images, and has a wide range of other uses, including data storage, microscopy, and interfe ...

" refers not to a stereoscopic effect, but to the coating that bundles light using formed

microlens A microlens is a small lens, generally with a diameter less than a millimetre (mm) and often as small as 10 micrometres (μm). The small sizes of the lenses means that a simple design can give good optical quality but sometimes unwanted effects ...

es. The lens design and attributes match the holographic area. The lenses may appear similar to the

Fresnel lens A Fresnel lens ( ; ; or ) is a type of composite compact lens (optics), lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. The simpler Dioptrics, d ...

es used in

overhead projector An overhead projector (often abbreviated to OHP), like a Movie projector, film or slide projector, uses light to Projector, project an enlarged image on a Projection screen, screen, allowing the view of a small document or picture to be shared ...

s. The resulting effect is that of a free-space display, because the image carrier appears very transparent. Additionally, the beam manipulation by the lenses can be used to make the image appear to be floating in front of or behind the glass, rather than directly on it. However, this display is only two-dimensional and not true three-dimensional. It is unclear if such a technology will be able to provide acceptable three-dimensional images in the future.

Working principle

The display design can use either front or rear projection, in which one or more video projectors are directed at the glass plate. Each projector's beam widens as it approaches the surface and then is bundled again by the lenses' arrangement on the glass. This forms a virtual point of origin, so that the image source appears to be an imaginary object somewhere close to the glass. In rear projection (the common use case), the light passes through the glass; in front projection it is reflected.

Interactive holographic screens

Interactive holographic screens add gesture support to holographic screens. These systems contain three basic components: *A

projector A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer type ...

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

*Two films The computer sends the image to the projector. The projector generates light beams which form the image on the screen. When the user touches the screen, a tactile membrane film reacts to these movements, generating electrical impulses that are sent back to the computer. The computer interprets the received impulses and modifies the projected image according to the information. The projector generates the beams of light that will form the image on the screen's film, which is adhered to the crystal support. These crystal lenses can be a maximum of across. The projector is usually located behind the screen and must be placed a certain angle above or below the user's line of sight to avoid the dazzling the user. Therefore, it must be trapezoidal projector, so it can compensate for the deforming of the images at this angle of

displacement Displacement may refer to: Physical sciences Mathematics and physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

. The films are thin sheets of plastic applied to the crystal that allow both visualization and interactivity. There are two types of films: *Screen film: This film can be opaque or transparent. It is possible to work with different degrees of opacity that can vary between 90% and 98%, depending on the application (interior, exterior,

natural lighting Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part ...

artificial lighting Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. ...

, etc.). *Tactile membrane: This film enables interactivity. Capacitive projected technology catches user gestures and sends impulses to the computer.

Uses

Most initial uses of this technology are advertising-related, such as shop windows.interactive shop windows
/ref> An interactive holographic screen can be mounted on the shop windows so that passersby can interact with it. Non-interactive holographic screens in shop windows can be coupled with artificial vision

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

to adapt ads based on the viewer's characteristics (age, sex, etc.). These types of screens are often used for the display of

Vocaloid is a singing Speech synthesis, voice synthesizer software product. Its signal processing part was developed through a joint research project between Yamaha Corporation and the Music Technology Group at Pompeu Fabra University, Barcelona. The s ...

s at concerts because they simulate the illusion of a holographically-projected virtual performer.

References

Adwindow adhesive projection screens
(In English, Spanish, French)

(In Spanish)
Globalzepp
(In Spanish)

Orizom
(In Spanish)
MediaScreen GmbH - Germany
{{DEFAULTSORT:Holographic Screen Holography Display technology Touchscreens

Working principle

Interactive holographic screens

Uses

See also

References