SMART GLASS TECHNOLOGY
INTRODUCTION
We know that, Smart glasses are computing devices worn in front of the eyes. Evidently their displays move with the users head, which leads to the users seeing the display independently of his or her position and orientation. Therefore smart glasses or lenses are the only devices which can alter or enhance the wearer’s vision no matter where he/she is physically located and where he/she looks. There are three different paradigms of how to alter the visual information a wearer perceives.
1. Virtual reality: The goal is to create a fully virtual world for the user to see, interact with and immerse into. The user sees this virtual world only, any other light sources are not affecting the eye. One significant difference to a simple screen is that the actions of the user affect the virtual world. In example movement affects what virtual content the user sees. A famous fictional example of a device creating a virtual world is the Hollyhock from Star Trek.
2. Augmented reality: The world is enhanced or augmented by virtual objects.The user can see the real world but also perceives virtual content created by a computing device and displayed by an additional light source which doesn’t prohibit the perception of the real world. Interaction with those virtual objects is a way of communicating with the computing devices.
3. Diminished reality: Objects are subtracted from scenes by filtering the light reflected or emitted by those objects towards the eye. This is most often used in combination with augmented reality to replace the diminished objects by some virtual objects.
Fig.Reality is augmented with a virtual object.
Devices with one display
1.Google Glass
One example of smart glasses with one display is Google Glass which runs the Android operating system. Its specifications are the following:
1. Weight: 50g.
2. Processing: 1.2 GHz Dual-core ARM Cortex-A9 CPU, PowerVR SGX540 GPU, 16GB storage, 682MB RAM. That’s roughly equivalent to the hardware of an IPhone 4.
3. Camera: 5MP still (2528x1856 pixels) or 720p video. There is no flash.
4. Display: It is a color prism projector with a resolution of 640x360 pixels.
5. Sensors: microphone, accelerometer, gyroscope and compass.
6. Interaction: There is a long an narrow touch pad which supports swipe and tap gestures. The camera can be triggered by a button.
7. Audio: There is a bone conduction transducer for audio. Sound reaches the inner ear in form of vibrations on the scull. Note that this technology is audible by the hearing impaired as well as persons with normal hearing.
8. Communication: It has no cellular modem which means it can not make phone calls on its own. It does have Bluetooth and WLAN 802.11b/g Google Glass is supposed to be used in combination with a smartphone and one of its main uses is to display notifications in a convenient and quick way It is supposed to be priced similarly to a high end smartphone but there are no official announcements concerning the exact price or release date.
Fig.Google Glass developer version.
2. Reckon MOD
There are also many devices designed for use during sports. Similar to Bruckner Travis they need to function in a rough environment but also should not be heavy. One example of dedicated sports smart glasses are the Reckon MOD. The Reckon MOD are snow sports smart glasses. They can operate at temperatures from 20 to 30 degree c, weigh approximately 65g and are water resistant. Interaction done through a wrist remote. The main use of Reckon MOD is displaying maps and performance statistics.
Bruckner TRAVIS
It is visible in figure that Google Glass does not have a very sturdy design and that it is made for consumers. It is not made for rough environments such as industrial sites or factories. One example of industrial smart glasses is the Bruckner TRAVIS shown in figure. This device is a lot heavier than Google Glass because the processing is done in a embedded PC worn in a vest. It is controlled with six hardware buttons and its main applications are streaming video and displaying manuals to employees.
Fig: Br¨uckner TRAVIS.
Devices with two displays:-
Smart glasses with two displays can affect everything the wearer sees and could display 3 dimensional content. This makes it possible to create a virtual, augmented or diminished reality. Both systems with two displays presented in this section need to be connected to a PC with a cable by which the virtual objects are created. In the future similar devices could be wireless and worn outside.
1.Cast AR
An exciting new technology which is used to create a augmented indoor reality is Cast AR. It has a projector above each eye which projects onto a retro reflector with 120hz each creating a 3D image. A retro reflector is a surface that reflects light back to its source with a minimum of scattering.
Nevertheless some of the light of each projector will reach the eye it is not destined for. To deal with this, Cast AR has active shutter lenses. The projectors are active in disjoint small time intervals. While the projector above one eye is not active the active shutter lens of that eye will stop any light from reaching that eye. This happens at such a high speed that the human eye can not notice. The result is a stereoscopic 3D image. Cast AR tracks head movement and orientation using an infrared camera and infrared LEDs inside the retro reflector. The exact position is calculated by triangulation in hardware on the glasses. This makes it possible to adjust the orientation of the virtual objects with only a few millisecond delay to head movement. Many people can share one retro reflector each seeing a different scene or the same scene from different angles. Another advantage of Cast AR compared to other smart glasses is that the angles.
Fig. Cast AR.
focuses on items in a distance rather than a screen in front of the eyes. This makes it possible to use Cast AR for long time periods without eye strain.
2. Oculus Rift
The oculus rift is a virtual reality solution which uses two display placed in front lenses close to the eyes of the wearer. There is one display in front of each eye, together they have a 1920x1080 pixel resolution on the newer protoOculus Rift Crystal cove prototype types. For Oculus Rift it is very simple to create 3D scenes because each display which may be adjusted. Oculus Rift tracks head movement using infrared LEDs like Cast AR but it also relies on a gyroscope and accelerometer. The advantage of tracking with a gyroscope and accelerometer is a very low latency, the disadvantage compared to the infrared solution is that over time errors accumulate and there might be orientation drift. By combining both methods Oculus Rift implements precise low latency head tracking. As already mentioned Oculus Rift is used to create a virtual reality. No light from the environment reaches the eye. The advantage is that there is no need for any display surface in the room and the whole field of vision can be occupied by virtual scene.
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Fig.Oculus Rift crystal cover prototype.
APPLICATION:-
It is used in different fields such as:
1. Education.
2. Medical.
3. Entertainment.
4. Universal remote control.
5. Documentation.
6. productivity.
7. sport.
8. commerce.
Note:- Source Internet.
