Technological advancement nowadays is moving to a faster pace. The latest display technology -Touch Screen Display, commonly used in our smart phones and tablet computers will move to a mere history in the coming future. Screenless Display, the emerging new display technology will replace this touch screen environment and will solve the problems at higher level, making life more comfortable. The main aim of the Screenless Display is to display or transmit the information without the help of a screen or the projector. Using this display, we can directly project images onto the human retina, open space and even to the human brain. It avoids the need of high weight hardware and it will provide privacy at a high rate.

This field came into progress during the year 2013 by the arrival of products like holographic videos, virtual reality headsets, retinal displays, mobiles for elderly, eye tap etc. At present, we can say that only part of the Screenless Display Technology is brought up which means that more advancement is necessary for a boost in the technology. Lack of space is one of major problem faced by screen displays. This problem will surely provide a pathway for screenless display.

What is Screenless Display?

Screenless Display was an excellent thought that came into many experts inorder to solve the major problems related to the device miniaturization. Lower space screen displays have made the need of screenless displays more than ever. Screenless, as the word suggests clearly means ‘no screen’. So, Screenless Displays can be defined as a display which helps to display and even transmit any information without the aid of screens.

When will screenless displays be fully available? This question is not yet answerable since many developments are under stage only. Since the displays are capable of projecting 3D images to the space, many disadvantages of 2D and screen based displays can be avoided. Displaying feature of it can be thought of as a projector without a movie. Using this excellent technology, we can even make our smart phone a TV. The countdown for the first screenless display has started now currently from the month of May 2014 onwards. Screenless Display currently uses Interactive Projection technology with visual display and 3D Projection Technology.

screen less display  screenless display technology

Figure1: Screenless Display

Screenless Display Types:

Screenless Display can be grouped into three main categories. They include Visual Image, Retinal Display and Synaptic Interface.

Visual Image Screenless Display:

Visual Image is a type of screenless display were the eye or the retina can recognize any screenless image. Holographic display, Virtual Reality Goggles and Heads Up Display are some present visual image screenless display examples. The display works on the principle that; light gets reflected by the intermediate object before reaching the retina. The intermediate object can be holograms, windows, or even LCDs.

Holographic messages that became popular through the ‘Star War Film’ are now becoming a truthful reality. Holographic Displays allow the display of three dimensional images by using simple components like Helium – Neon Laser, a Lens, an object, mirror and a holographic film. The laser beam used will initially create a plasma environment. When the laser and object beams coincides, a 3D image will be projected. The projected image will appear to be floating in air. Presently, MIT’s Media Lab reported a holographic color video display (inexpensive) with the resolution of TV. Latest fiction movies the ‘Iron Man’ and ‘Avengers’ have shown this technology in more advanced form. This advancement can be expected in the coming future.

Holographic images Holographic image projection of car

    Figure 2: Holographic images

Virtual Reality Goggles (VRG) is an eyewear display device. Wearer can view and interact with a series of computer generated images. Consist display screens in front of face. Images can be projected with sound and video, allowing it more popular for entertainment applications. Presence of polarized lenses is the major feature of VRG. These lenses will show two images, one per each eye and the brain combines them to form a three dimensional image. They show an illusion of depth. Many of these goggles are accompanied by head tracking systems connected to a computer, thereby adjusting images seen by the wearer as they move around.

‘World of Warcraft’, ‘Quake2’ are some popular games that can be played using VRG. The famous ‘Oculus Rift ‘and the recent ‘Google’s Cardboard Virtual Reality Goggles’ is an evidence that VRG is on its way. Now many DIY VRG are coming out since it requires only components like a smartphone, two lenses, a rigid paper or cardboard and some tape. ‘Sony Headman’ a virtual reality headset by ‘Sony ‘is also gaining popularity now.

             Figure 3: Oculus Rift


              Figure 4: Virtual Reality Goggles

Heads Up Display (HUD) are transparent displays. They can be useful for aeroplanes, automobiles, computer games etc. The device will project information on a windshield such that the users do not need to look away from their field of view. An ordinary HUD contains a projector unit, combiner and a computer as its components. Projector Unit will project the image and the combiner will redirect the projected image such that we can see the field of view and the projected image at the same time. Computer is an interface between projector unit and data to be displayed.

Recent ‘Portable Garmin’s HUD’ for automobiles projects navigation information onto the windshield. The device is placed on the dashboard of the car which works wirelessly with a Bluetooth enabled smartphone. Estimated arrival time, lane assist, speed, traffic and safety camera alerts are the informations displayed. ‘Russian Hudway App’ utilizes just a smartphone (no projector) to act as HUD. It keeps track of speed, location, coming curves and hills in road, and distance by using the device accelerometer and GPS. Many aircrafts (e.g.: Embraer 190, PZL TS-11 Iskra), air buses, cars (e.g.: BMW E60, 2013 Toyota Prius) are using this device. 

HUD on aircraft

Figure 5: HUD in aircrafts

HUD on car

Figure 6: HUD in car

Visual Image Screenless Displays has the advantage of creating and even manipulating the images upto any size. Manipulation is possible in the Image Mode; also multiple bitmaps can be composited together in the Object Mode in this category of displays. In Visual Screenless Displays, EYE Files are created. EYE Files generally include all the images that are loaded. The ‘Export Project Command’ in ‘File’ will create the EYE File. These files will provide a provision to save any unsaved visual image as bitmaps into it. Catalogs of images can be created in an EYE File. ‘Export Editor Command’ in ‘File’ will allow to browse the desired image files on disk to place it under a common catalog. Thus visual catalog files can also be created in the EYE File. Visual Image Screenless Displays with different advantages and better advancements will surely provide a roadway for screenless displays.

Retinal Display:

Virtual Retinal Display (VRD), a screenless display technology allowing the image directly to be projected on to the retina. In VRD, no real image is produced. It just beams the image to our eye balls directly.  The user will feel that the display is floating in the space in front of him. Retinal Scan Display and Retinal Projector are some common popular names of it. Compared to other displays, it uses narrow band color, coherent light and allows short transient light emission. The VRD was initially invented by Kazuo Yoshinaka in 1986.Later work at the Human Interface Technology Lab at University of Washington had brought out a VRD  system in 1991.Now VRD is under more research.

block diagram of retinal display

Figure 7:  Retinal Display block diagram

VRD uses a photon source generating a coherent beam of light. Laser Diode like coherent source will help the VRD to give a diffraction limited spot on retina. The light beam from the photon source is intensity modulated. Intensity Modulation of light beam is done generally to match the intensity of the image. Now the modulated beam undergoes beam scanning. Beam Scanning allows keeping image pixels properly on the retina. In the beam scanner both raster mode and vector mode scanning takes place. After the scanning process, the optical beam projection to the retina takes place. When the coplanar property between the entrance pupil of the user and the exit pupil of VRD is achieved, a spot like beam will be focused to the eye. The spot focused through the eye will draw an image on the retina. Drive electronics will allow synchronization of scanner, modulator and coming video signal. Through synchronization a stable image will be formed. Its said that more compact VRDs will be available with the MEMS technology.

Figure 8: How vision works

HOw screen less display works

Figure 9:  Retinal Projection

In January 2014, Glyph Company had raised a sum via KickStarter with the aim of bringing personal gaming and cinema device using retinal display. Eye Tap and Bionic Contact Lenses are some present day examples for retinal displays. Eye Tap, is a display device that can act as a camera and a monitor. It can be worn on the eye. Generally a beam splitter is the major component of the eye tap. Now the eye taps are replaced by the smart Google Glasses.

google glass mepits

google glass

               Figure 10 :  Google glass

Bionic lenses use components like electric circuit with red light-emitting diodes, a sensor and a micro size silicon chip for visual display. Controlling the display intensity and all functions by voice is the major feature. Infrared rays help transfer of information within the lenses. Many research and developments are taking place with these lenses.

Synaptic Interface:

Synaptic Interfaces does not use light at all and the visual image is directly given to the brain. The technology is in the advancement mode and it is now been tested on humans too. This is useful for security system, effective communication, education, business, planning and broadcast. Success was achieved in sampling video signals from eyes of horseshoe crab through their nerves. Also, the video signals from electronic cameras into the creatures' brains were also sent successfully.

Synaptic interface

                                                                       Figure11: BRAIN Computer Interface on Humans


 Brain-computer Interfaces allows direct communication between the brain and the external device. Brain Machine Interface, Mind Machine Interface, Direct Neural Interface and Synthetic Telepathy Interface are some common names by which they are known. Can you guys imagine a computer been controlled using our mind? Then this imagination is coming to a reality through synaptic interfaces. Recently Duke University reported that by connecting the brains of two mice over the Internet, the mices were able to cooperate and perform tasks. In 2013 Harvard University reported that they established a link between the brains of rat and human.

In 2013, MIT reported that they have implanted false memory into the brain of a mouse. Now much research is taking place related to this. The advancement in the technology will make the future world in such a condition that even a blind person can drive vehicles.

Screenless Display Advantages & Disadvantages

The products belonging to this emerging technology bring out many advantages compared to the existing products with the old technology. While taking the images into consideration, the present screenless displays have the ability to present 3D images, far point images and an image with higher resolution one. Good brightness and contrast and large angle of view are the other essential advantages. With the increasing use of the screenless products, we can expect a decrease in the cost also in the coming future. Lower power consumption, light weight, and providing better privacy are some essential advantages achieved in all the smart screenless display products. The screenless displays will boost up the field of entertainment at a great stage.

Disadvantages faced now are basically the higher cost and limited availability of the screenless display products. Most of the technologies required for the outward of screenless display are in development stage only. Many problems related to eye sight can arise since the products require close interaction with the eye.

Futurescope of Screenless Display

Screenless Displays is on the way of progress. Technological experts are taking great efforts in researching the topic day by day, so we all can expect a great revolution in the field of displays. Many IT companies and the best labs in the world are trying to bring out many products. The coming era will surely be a virtual world more than our expectation. In 2001, Microsoft Company has started their project on Interactive Table. Many innovations are coming out in the near future related to this. Google is researching more on screenless tablet computers and smartphones, eventhough they have proposed a system based on the concept of virtual image. Also, Google is developing a compact video camera which uses this new advancing technology.

Its said that the electronic beam lithography will surely help the future screenless display. So many labs are under research to bring out more advancement. For Artificial Retinal Displays, the technology of microvision must be enhanced. Microvision technology can bring out many exciting screenless display products. So, the technology is under research and development for the better future of screenless display. Companies are working out to bring more screenless mobiles, TV’s, cameras and laptops for the coming generation. Intelligent Glasses that can translate foreign text while reading is a current innovative product brought out by Japan. The product will allow the wearer manipulating virtual images in their field of view. More advancement is taking place with the product, so that the size, weight and battery life can be improved. Adobe Systems are working to bring out more innovations. Its said that by 2020, the world will become a virtual one and more exciting.