Screenless Display Technology Provides Virtual Reality Interface Raju, Maksudul Hasan (12-21361-2) American International University Bangladesh
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Abstract. This paper discusses incarnation of the screenless display which is an emerging new technology. It has become a good prospect in the near future for a wide range of applications. As the name means that screenless display is an interactive projection technology without using screens. It includes three different working principles such as Visual image, Visual retinal display and Synaptic interfaces. This technology will bring breakthrough revolution and solve the problems related to the device miniaturization of the futuristic technology.
Keywords: Hologram,Screenless,Graphene,laser,Raster-pattern,photographic plate
1
Introduction
Screenless display is the advanced display technology in the field of the computerenhanced technologies [3][7]. As the word screenless, refers clearly means having no screen. A display which helps to display and dispatch any information without the aid of screens can be ascertained as screenless Display [9]. The lack of space which forges a major flaw for screen-based displays acts as an accrual scope for screenless displays. Low power consumption, low cost, wider view, high portability, easier access and enhanced privacy are some of the factors which also drive this technology [8]. It is the projection of visual information through the deflection of light where the light is usually deflected through mirrors, fog or plastic films [1]. Although, several research is still going on whether air can be used to deflect the light to change the whole spectacular view but these attempts have found few results to date [5]. Apart from this, there are another types of screenless displays which do not require an intermediate medium for the projection of light. This technology segment includes smart phones, laptops, televisions, touch-less interfaces, virtual reality and augmented reality. Screenless Display can be classified into three main categories [8][9]. They comprise Visual Image, Virtual Retinal Display and Synaptic Interface. Visual image refers the things that can be seen by the human eye on the open space such as holograms [10]. Retinal display indicates the display of image directly onto the human retina and Synaptic interface which means sending information directly to the human brain.
2
Literature Review
In 2013 screenless display market has witnessed factual growth and according to the MIT latest technology review, it has become a new rage of development for the next GEN-X .Screenless display was first introduced by the mobile phone named OWASYS 2CC [8]. Google, Microsoft, Apple, Kapsys, Displair and Avegant are the key players in the global market, hence several researches renowned IT sector companies are being driven for the future development of this emerging new technology such as mobile phones for elderly, blind people, bionic contact lenses, virtual reality headsets and holograms [4]. Google is researching more on screenless tablet computers and smartphones, Google Glass and Cardboard Virtual Reality use the concept of screenless display. In cardboard, two polarized lenses show two images, which helps the brain combines to create a 3D image. Given the illusion of depth the brain offers a type of virtual reality. Goggle offers another wearable way to interact with screenless display which is named Google glass and anyone can wear it [9]. Therefore, using virtual retinal display several companies had already raised with the aim of commercializing personal gaming and cinema devices. In the field of the hologram projection screenless displays are also broadly applicable because holographic images can be generated in three dimensions [6]. Recently researchers at Swinburne University of Technology have discovered nanoscale pixels of refractive index through a photonotic process and found the capacity of a technique using graphene oxide [5] and complex laser physics to create a pop-up tiny floating 3D holographic image which is visible to the opened eye. Graphene enabled floating display is based on the principle of holography because it is a two dimensional carbon material with extraordinary electronic and optical properties. Though there is no limitation for the up scalability of graphene 3D display it can allow images up to 1cm only [5].
3 3.1
Hardware Design Model Visual Image
Visual image screenless display perceives any kind of screenless images with the help of the human eye [7][8]. Hologram, heads up display, virtual reality are well-known example of visual image. Holography is the technique to reconstruct wave fronts of light with both amplitude and phase information for real 3D images [5][6]. A hologram is recorded like a compact disk and can be reconstructed when it needs in Figure 1 (a)[9]. By capturing the reflected light from the intermediate object it can be accomplished. Using atmospheric nitrogen and oxygen, this system focuses a beam of laser light which creates plasma medium in the environment and able to display holographic images. Firstly, a laser beam is passed through beam splitter and divides the beam into two parts. One is illumination beam and another one is made to fall on mirror. The object which is placed in front of beam splitter is illuminated by the illumination beam and the reflected beam from object is captured on the photographic plate [10]. At the same time, the second beam falls on the mirror and passes to the reference
(a) Recording a hologram
(b) Reconstruction of hologram
Fig. 1: Visual Image beam which is made to fall on recording medium Figure 1 (b)[9]. In this whole structure the collocation of mirrors can be adjusted to reflect all the light in every direction with equal consistency. Now at the recording medium the beam coming from object and mirror interferes and imprints on photographic plate. Thus, the recording of hologram is finished. In order to view recorded data the original beam of laser light used while recording [2]. When reconstruction needs, the photographic plate (hologram) is illuminated by the original beam and it constructs the diffraction phenomenon. Thus it sprinkles the light in the air and the images can be viewed which is called as virtual image. 3.2
Virtual Retinal Display
Virtual Retinal Display allows to project a screenless image directly onto the retina of the viewer instead of using any intermediate object for light reflection [8] and makes the sense that it is floating in the space. One of the well-known example of retinal display is Google Glass [9]. A block diagram of the virtual retinal display consists of photon generation, intensity modulation, beam scanning, optical projection and drive electronics which is shown in Figure 2(a)[7]. When photon generation block generates a coherent beam of light, the laser
(a) Block diagram of Retinal Display
(b) Functional block diagram of VRD system
Fig. 2: Virtual Retinal Display diode like coherent source with retinal display to give a diffraction onto the retina [7, 9]. The light which is generated from photon source is intensity modulated. Intensity Modulation of the light beam is done modulated to match the intensity of the image. After accomplishing modulation the source can be modulated without delay, if it has enough modulation bandwidth. The modulated beam undergoes beam scanning when each pixel is properly positioned on the retina.In Figure2(b)[7]shows, there are various scan patterns. Raster-pattern method of image scanning is used in calligraphic mode and it allows the VRD to be driven by standard video sources. To draw a row of pixels a horizontal scanner is used to move the beam. The vertical scanner draws another row of pixels. After scanning, optical beam projection properly takes place to the retina [9]. Then the coplanar substance between the entrance pupil of the eye and the exit pupil of VRD is achieved and a spot like beam focused to the eye which can
draw an image on the retina. Finally drive electronics perform synchronization [7] of scanner, allow intensity modulator and coming video signal in such a way that a well-conditioned image is formed. 3.3
Synaptic Interface
In synaptic Interface visual information is transmitted directly to the brain without using light [8]. Synaptic Interfaces allow direct interaction between the human brain and external devices like computer or other electronic devices. They are known as some common names like Brain Machine Interface, Direct Neural Interface, Mind Machine Interface and Synthetic Telepathy Interface [9]. This technology was accomplished by sampling the video signals from horse crab eyes through their nerves and the other video signals from the electronic cameras were sent successfully into the brains of creatures.
4
Conclusion
This paper has discussed about screenless display and its conveniences and drawbacks. Though the technology is evolving, this needs plenty of knowledge and process for the development is on the way of improvement. Hence, prototypes and special experimental models are now being built and their cost per unit is high but excrescent development and research offer significant hope for the upcoming screenless device’s future to make lives more comfortable.
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