HTC VIVE :An amazing VR(virtual reality) product

HTC is one of the leading manufacturer of VR headsets and other devices

HTC Vive VR head set

Content Highlights

• HTC VIVE
• How it works
• Unique features included in HTC VIVE VR headset
• HTC VIVE for gaming
• SteamVR™ Tracking technology
• Where to buy and best deals for HTC VIVE
• System requirements for HTC VIVE VR

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HTC VIVE:The Ultimate VR effect

HTC Vive is room scale virtual reality head-mounted display launched by HTC which provides fully immersive Virtual Reality effect.Vive is brought to you by HTC and Valve. Uniting passion, talent, and innovation, Vive delivers on the promise of VR with best-in-class technology and content.

How HTC VIVE Works

This headset is designed to utilize "room scale" technology to turn a room into 3D space via sensors, with the virtual world allowing the user to navigate naturally, with the ability to walk around and use motion tracked handheld controllers to vividly manipulate objects, interact with precision, communicate and experience immersive environments.

HTC Vive VR ser enables fully immersive VR

Awards won by HTC Vive

Unveiled during HTC's Mobile World Congress keynote in March 2015, the HTC Vive has since been awarded over 22 awards in CES 2016, including best of CES.

Best of CES 2016,Best Entertainment- Slash Gear

Unique features included in HTC Vive

Front facing camera blends real world elements into the virtual world

front cam

110 degree field of view

wide lenses

32 headset sensors for motion tracking

head set sensors

2160*1200 combined resolution and 90 Hz refresh rate deliver eye popping graphics and smooth action

HTC Vive for gamers

HD haptic feedback and intuitive gestures mean playing games and interacting with the virtual world comes naturally. Vive’s two wireless controllers feature 24 sensors for unobstructed movement, meaning you can do more in VR than ever before.

Haptic or kinesthetic communication recreates the sense of touch by applying forces, vibrations, or motions to the user.This mechanical stimulation can be used to assist in the creation of virtual objects in a computer simulation, to control such virtual objects, and to enhance the remote control of machines and devices. Haptic devices may incorporate tactile sensors that measure forces exerted by the user on the interface.

Intuitive gesture:gesture sensing through intuition rather than from reasoning or observation

Multifunctional track pad provides effortless precision and HD haptic feed back.Dual stage triggers with HD haptic feed back brings VR experience to a new level.Two handheld controllers each have 24 sensors for accurate tracking.

htc handheld controller

trackpad

Sensors on handheld device

SteamVR™ Tracking technology

SteamVR™ Tracking technology

Breakthrough SteamVR™ Tracking technology lets the headset and controllers know in real time where they are within a room. Freely explore and interact with objects, characters and environments. Room-scale VR puts you at the center of everything.

two base station provides 360 degree motion tracking for superior VR experience

how SteamVR™ Tracking technology works

The tracking system gives you your own personal GPS right in your living room,accurate to a millimeter.Beacause LASERS roomscale VR gives you the freedom to move around and to gain an entirely new perspective on in-game world.If you get too close to the real world while in the virtual one ,the chaperone will give you a gentle(Virtual) reminder.

Vive port

Viveport is a place where people can discover the latest and greatest in VR content and experiences.interactive Videos, games and much more

Vive provides you with a handful of VR contents at vive port.

What you need for experiencing fully immersed VR using HTC Vive

How to buy HTC Vive VR head set

You can purchase HTC Vive directly from vive store  or from leading online stores amazon and ebay.

It is also available at microsoft store

HTC Vive best buy

HTC Vive VR set is priced between $839.99 $600 and $800.

Price of HTC Vive at various online shopping karts :

• eBay-$839.99 (new)
• eBay-$650 (used)
• amazon-$799.99
• microsoftstore- $799.99
• Vive store-$799.99

HTC vive system requirements

HTC has tested systems and worked with industry-leading manufacturers to bring you computers ready for Vive right out of the box. From graphics cards and processors to memory and storage space–these computers deliver a superior VR experience.

Recommended computer spec for installing vive

• Processor: Intel™ Core™ i5-4590 or AMD FX™ 8350, equivalent or better
• Graphics: NVIDIA GeForce™ GTX 1060 or AMD Radeon™ RX 480, equivalent or better. For additional graphics card options, view the complete list.
• Memory: 4 GB RAM or more
• Video output: 1x HDMI 1.4 port, or DisplayPort 1.2 or newer
• USB: 1x USB 2.0 port or newer
• Operating system: Windows™ 7 SP1, Windows™ 8.1 or later or Windows™ 10

You can also check your PC using a small exe file provided in htc vive site.

Self Driving Car Technology:Latest developments

In a decade Autonomous/driverless vehicles will rule the streets of major cities around the world

Content Highlights

• Autonomous/selfdriving/driverless car technlogy
• How does a self driving car works
• Architecture of autonomous vehicles
• Google self driving car project
• Tesla autonomous vehicle project
• Selfdriving technology:Recent developments
• Advantages and disadvantages of selfdriving autonomous vehicles

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Driver-less car technology:An Overview

'When will self driving cars be available?'Many people are searching this phrase in different search engines.What this implies?.People are eagerly waiting for a perfect driverless car.Autonomous cars are already out there in market.But are they safe enough?Are they ready to compete with cars driven by humans?To what extent these vehicles are autonomous?.Questions goes like that.Let us see how far self driving car technology has reached so far.In this article let us have a look at current self driving car technologies and autonomous car researches happening around the world.

How do self driving cars work?

An autonomous car (driver-less car, self-driving car, robotic car) is a vehicle that is capable of sensing its environment and navigating without human input.Autonomous cars can detect surroundings using a variety of techniques such as radar, lidar, GPS, odometry, and computer vision.

Electrical/Electronic system architectures of autonomous cars

Principal functions of a autonomous driving system can be categorized into to three.

1. Sensing

2. Decision making/planning

3. Control/execution

Sensing:Autonomous cars can detect surroundings using a variety of techniques such as radar, lidar, GPS, odometry, and computer vision.

Decision making/planning:Decision making can be done by programmed processors.It can be also achieved by artificial intelligence systems.

Control/executions:Decision based on the input by sensors should reflect in vehicle movements.This is primarily done by actuators which regulate speed and direction of the vehicles.

sensors used in self driving cars(image courtesy:http://www.automotivenl.com/)

How far we have reached in autonomous vehicle technology?

Many companies have developed self driving machines so far.Some of the notable projects are discussed here.

Google self driving cars:

According to google ,"google cars use their sensors and software to sense objects like pedestrians, cyclists, vehicles and more, and are designed to safely drive around them"

How it drives

The car processes both map and sensor information to determine where it is in the world. Self driving car knows what street it's on and which lane it's in.

Sensors help detect objects all around us. The high end software classifies objects based on their size, shape and movement pattern. It detects a cyclist and a pedestrian in this case.

The software predicts what all the objects around us might do next. It predicts that the cyclist will ride by and the pedestrian will cross the street.

The software then chooses a safe speed and trajectory for the car. Car nudges away from the cyclist, then slows down to yield to the pedestrian.

Major functional components of google self driving cars

Google team is working toward vehicles that take you where you want to go at the push of a button. Google is adding components to existing cars like their Lexus SUVs, then began designing a new prototype from the ground up to better explore what should go into a fully self-driving vehicle. They managed to remove the steering wheel and pedals, and instead designed a prototype that lets the software and sensors handle the driving.

Google started the self-driving car project in 2009.In 2009, they started testing self-driving technology with the Toyota Prius on freeways in California.In 2012, they began testing with the Lexus RX450h. Next, google cars shifted focus to city streets, a much more complex environment than freeways.Google unveiled an early construction of their new prototype vehicle in 2014. It’s designed from the ground up to be fully self-driving.

Google's fully autonomous car prototype

After months of testing and iterating, google delivered first real build of their prototype vehicle in December 2014.Still google is continuing research and development of their self driving cars.Before going into the commercial production they have address a serious of problems including self driving cars compatible roads,signal systems,precise navigation technology etc.Few crashes were also reported recently which demand google more safe autonomous vehicles in the future.

Google is publishing its Self-Driving Car Project Test Report every month.You can check Google Self-Driving Car Project Monthly Report from below link.

• Google self driving car monthly reports

Tesla Self driving car project.

Leading electric car manufacturer Tesla claims 'All Tesla Cars Being Produced Now Have Full Self-Driving Hardware needed for full self-driving capability at a safety level substantially greater than that of a human driver'.Eight surround cameras provide 360 degree visibility around the car at up to 250 meters of range. Twelve updated ultrasonic sensors complement this vision, allowing for detection of both hard and soft objects at nearly twice the distance of the prior system. A forward-facing radar with enhanced processing provides additional data about the world on a redundant wavelength, capable of seeing through heavy rain, fog, dust and even the car ahead.

Tesla self driving car sensor distribution

Model S and Model X vehicles with this new hardware are already in production, and customers can purchase one today.

Tesla promises they will further calibrate the system using millions of miles of real-world driving to ensure significant improvements to safety and convenience.

Apart from google and Tesla, leading automobile manufactures like Volvo,BMW,Mecedez etc.. are also have launched their own versions of fully/partially autonomous vehicles.

Recent advances in self driving vehicle technology

• Delphi, formed out of the former parts division of General Motors, and Mobileye, a rising Israeli company known for producing the sensors and other technology that help cars recognize obstacles in the road, had formed a partnership to provide self-driving components to automakers by the end of 2019.Mobileye and Delphi said they expected to demonstrate an early version of their system in January at the 2017 International CES, the annual consumer electronics show, in Las Vegas and to begin production of a commercial version within two years.Mobileye is already a vendor of computer-vision technology and other related systems to carmakers. For Delphi, the partnership is an extension of its other efforts to develop self-driving cars, including a project with the government of Singapore to field a test fleet of driverless taxis. In 2015, a driverless car built by Delphi completed a 3,400-mile trip from San Francisco to New York in nine days 
• Delphi-Mobile eye duo is adding computer-chip giant Intel to the partnership to accelerate a project meant to deliver a fully self-driving vehicle system by 2019. 
• Reports suggest that Apple is developing an electric iCar to rival Tesla.Apple is now focusing on an autonomous driving system.Apple has not made official announcement regarding its driver-less car projects.But,with news of a letter penned by Apple to US transport regulators about self-driving cars strengthens the rumours of iCar project under cover.

Major challenges in self driving car technology

• Creating (and maintaining) maps for self-driving cars is difficult work.Google's self-driving cars work by relying on a combination of detailed pre-made maps as well as sensors that "see" obstacles on the road in real time. Both systems are crucial and they work in tandem.
• Driving requires many complex social interactions — which are still tough for robots
Driving is an intensely social process that frequently involves e interactions with other drivers, cyclists, and pedestrians. In many of those situations, humans rely on generalized intelligence and common sense that robots still very much lack.Artificial intelligence can solve this problem to an extent.
• Bad weather makes self driving more complex and trickier.Conditions like wet and slippery roads,bad visions in fog etc..
• Better Roads:Especially in developing and under developed countries putting self driving machines on road is not going to be accomplished in near future.Self driving requires compatible roads.Such roads should have perfectly marked lanes,fool proof signal systems etc..
Better software:Driving in the United States is actually incredibly safe, with fatal crashes occurring once every roughly 3 million hours of driving. Driverless vehicles will need to be even safer than that.
• Reckless Drivers/Unpredictable Humans:Predicting behaviour of a reckless/drunken driver is nearly impossible.
• Law and regulations:requires a completely new set of laws and regulation for these category of vehicles.

Autonomous vehicles pros and cons

Pros

• Since 81 percent of car crashes are the result of human error,there would be fewer accidents, as human error would be nullified.
• It would be accessible to anyone. Children, senior citizens, visually-impaired or other impaired citizens.
• There would be a reduced need for road signage, as the car would receive information electronically through signals.
• There would also be a better management of traffic flow, which would be monitored over a controlled system.
•  Less parking structures and parking headaches would be required, since your car could actually drop you off and locate a parking space farther away.
• There would be fewer cars on the road, as families would only need one car to suit the needs of every member. This would sequentially cut down on carbon dioxide emissions, thus being more environmentally friendly.
• Sensors in the autonomous cars allow vehicles to ride closer together, therefore allowing more cars on the road with actually less traffic.

Cons

• Car enthusiasts would most certainly disagree to give up driving their own vehicle. To many, driving a car means much more than reaching a simple destination, as it seems to be reduced to when adopting autonomous cars.
• It would be an economic disaster, if autonomous cars were implemented everywhere. Job losses would be monumental, as there would no longer be a need for professional drivers, such as cab and lorry drivers.
• Autonomous cars would be much more expensive to buy, not to mention setting up electronic sensors on every accessible road or highway.
• Autonomous vehicles rely heavily on GPS satellites. If a signal were to be blocked, this would affect the cars functionality.
• The most savings in terms of cost, time, and lives is going to come from when more people "opt in" to the service. If self-driving cars are not adopted widely, accidents can and will still happen.
•  If other technology fails, such as traffic signals that the cars rely on, there's no accounting for human traffic signals.
• Autonomous vehicles are still undergoing research and can’t be trusted to operate without error, until further advances are made. Until then, they should be kept as ideal prospect for the future, which should still be visualized with caution.

At present self driving car technology is in its amateur phase.Autonomous vehicle technology will be one of the most competitive field in coming years.Many leading companies are working on autonomous vehicle technology.Lets hope this competition will bring out a perfect model of a driverless car in near future.

How Fingerprint Scanners in mobile phones Work?

Fingerprint Scanners in smart phones

Latest smartphones like google pixel feature capacitance sensor based fingerprint scanners.

Content Highlights

• Fingerprint scanners in smartphones
• Structure and working of fingerprint sensors in smartphones

Underlying technology of Fingerprint Scanners in smart phones are quite different from ordinary fingerprint sensors.Fingerprint sensors can be broadly classified into two.Optical sensors and capacitive sensors.

An optical fingerprint sensor is an electronic device used to capture a digital image of the fingerprint pattern. This image is digitally processed to create a biometric template (a collection of extracted features) which is stored and used for matching.Fingerprint sensors in modern smartphones are capacitive sensors.

The diagram below shows a simple capacitive finger print sensor. The sensor is an array of tiny sensing cells. Each cell has two conductor plates.Working of this sensors are similar to the working of touch sensors.

capacitance based finger print sensor cells

The sensor is connected to an electronic circuit which sense even minute current variations.Working of this sensing circuit is beyond the scope of this article.Main component of this sensing circuit is an amplifier which amplifies the minute current variations.You might have studied in your high school physics "The factors affecting capacitance":

• Plate Area.
• Plate Spacing ( distance between the plates )
• Dielectric Material.

Finger you are placing over the sensor will act as dielectric.When finger's ridges are placed over conductive plates, it increase the capacitance between plates, while an air gap(valley) will leave the charge at the capacitor relatively unchanged.In short the capacitor in a cell under a ridge will have a greater capacitance than the capacitor in a cell under a valley.Variation in capacitance will result in current flow.This variation is amplified by the sensing circuit.This analog signals are converted into digital signals using an ADC(Analog to Digital Converters) and required signal processing is carried out to extract the feature of a fingerprint.

What is AMOLED Display?

AMOLED display (Active-matrix organic light-emitting diode)

Samsung is the largest Manufacturer of AMOLED displays

Content Highlights 

• What is an LCD display 
• What is an OLED 
• How does an OLED works 
• Types of OLED display 
• AMOLED(Active) and Passive matrix OLED displays 
• Advantages and disadvantages of AMOLED display 
• Super AMOLED display

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Expansion of AMOLED is Active-Matrix Organic Light-Emitting Diode.Let us see what each term means.Let us start with LED.

LED Display

An LED display is a flat panel display, which uses an array of light-emitting diodes as pixels for a video/picture display.As you know an LED( light-emitting diode) is a p-n junction which emits light when electric current is passed through it.In an LED dispaly panel , these LEDs are shrunk down dramatically and arranged in red, green and blue clusters to create an individual pixel that can reproduce white light and various colors.

LED V/s LED back-lit LCD

LED displays are used in large displays like leaderboards,advertising pannels etcc. LED TVs and Smartphones displays are usually LCD with LED back-light. Usually consumers think that LED TVs have LED display. It is LED backlit LCD

OLED Display

The O part in OLED stands for organic.In an OLED, a thin layer of organic material is placed between two conductors, which is then used to produce light when a current is applied.At least one of these electrodes is transparent.Properties of these organic material is analogous to semiconductors.

Working principle of OLED

Originally, the most basic polymer OLEDs consisted of a single organic layer.But modern OLEDs incorporate a simple bilayer structure, consisting of a conductive layer and an emissive layer.

During operation, a voltage is applied across the OLED electrodes such that the anode is positive with respect to the cathode.Current flows through the device from anode to cathode(direction of electrons flow is opposite to current direction).Emmissive layer is more negative(electrons are the majority carriers) and conductive layer is more possitive(holes are the majority carriers).

As more electrons are injected into emmissive organic layer(2) at the cathode(1) and withdrawn from conductive layer (4)at the anode(5). Electrostatic forces bring the electrons and the holes towards each other and they recombine. This happens closer to the emissive layer, because in organic semiconductors holes are generally more mobile than electrons. The decay of this excited state results in a relaxation of the energy levels of the electron, accompanied by emission of radiation whose frequency is in the visible region. The frequency of this radiation depends on the band gap of the material.

Schematic of a bilayer OLED: 1. Cathode (−), 2. Emissive Layer, 3. Emission of radiation, 4. Conductive Layer, 5. Anode (+)

Classification of OLED Displays

OLED displays can be classified into passive matrix OLEDs(PMOLEDs) and active matrix OLEDs (AMOLEDs) based on their driving circuit.In a passive matrix, a complex grid system is used to control individual pixels, where integrated circuits control a charge sent down each column or row. But this is rather slow and can be imprecise. Active Matrix systems attach a thin film transistor (TFT) and capacitor to each LED.Each OLED pixel can be accessed by activating corresponding row and column , allowing for faster and more precise control.

Active v/s Passive matrix OLED

Pros and Cons of AMOLED Displays

Pros

IPS display is the main competitor of AMOLED display.Samsung is the leading promoter of AMOLED displays.But many leading brands like iPhones and HTC still use IPS display.So here we are analyzing the Pros and Cons of AMOLED Displays in comparison with IPS Displays

• The panels are thinner: Allows for slimmer devices. AMOLED displays are much thinner than IPS Displays.
• IPS LCD displays need back-lighting.But LED pixels in AMOLED display produce light their own.
• Intense black color:In AMOLED display each pixel can be completely switched off,this in turn produces pure black colour.
• High Battery Life: An AMOLED consumes less power than IPS.
• High Contrast: AMOLED provide better contrast ratios.

Cons

• Expensive production: The technology needed to develop AMOLED panels is very expensive.
• Organic materials have limited lifespan, far shorter than the lifespan of LED or LCD. lifespans of each colour-specific organic material varies. Red and green OLED films have longer lifespans compared to blue OLED films. This variation results in colour shifts as a particular pixel fades faster than the other pixels.
• Low definition images: less sharper images
• Less accurate white colour when compared with IPS display
• Compared with an LCD, an AMOLED display is difficult to view in direct sunlight due to reduced maximum brightness and lack of backlighting

Super AMOLED displays

An AMOLED touchscreen usually has an extra, touch sensitive layer on top of the screen, but with Super AMOLED designers able to integrate touch sensitivity into the screen itself.This was designed by Samsung.The result of this is that not only is the screen thinner, lighter, more touch sensitive and less power-hungry, but without that extra layer it's also far less reflective than a typical AMOLED screen, making it easier to view in bright sunlight.

Phones with amoled display

Apart from Samsung, many leading smartphone manufactures have started opting AMOLED displays for their latest model.Here you can find some leading smartphones with AMOLED display.

• Huawei Mate 9 Pro
• One Plus 3
• Huawei Enjoy 6
• ZTE Axon 7 mini
• Asus Zenfone 3 Deluxe
• Samsung J1 2016
• Samsung W2017
• Honor Note 8

• Samsung Galaxy Note 7
• Xiaomi Mi Note 2
• Oppo F1 Plus
• lenovo Moto Z
• Meizu Pro 6
• Google Pixel / Pixel XL
• Vivo Xplay 5
• Samsung Galaxy C9 Pro

Technologies used in Google Pixel smartphone

Finally Google launched its own branded smartphone ,Google Pixel.Let us have a look at some unique features and technologies used in  Google Pixel and Google Pixel XL

Google pixel and Google pixel XL have incorporated various modern technologies to give an edge over its rivals.

Camera

According to google "The highest rated smartphone camera. Ever.With a best-ever 89 DxOMark Mobile score, Pixel's camera lets you take brilliant photos in low light, bright light or any light"

Main camera has 12.3MP

Google Pixel comes with a 12.3MP primary camera

Phase detection autofocus:The phase detection/AF system is a very complex system that sees improvements pretty much every time when a higher end camera line is refreshed. Over the years, the number of autofocus points have been increasing, as well as the number of more reliable cross-type autofocus points.

Laser detection autofocus:It makes use of laser sensor system to adjust the focus of the handset's rear camera.

Google Pixel combines Phase detection and Laser detection to improve auto focusing capabilities of its rear camera.

f/2.0 Aperture:What does an "f/2.0 lens" mean?-Simply put, it's the ratio between the focal length of the lens and the aperture / hole that lets light through the lens into the camera.For example, an f/2.0, 50mm lens would have a aperture/hole diameter of 25mm.So the large the 'f' number, the smaller the opening.So,f/2.0 lens in a Google Pixel/Google Pixel XL   lets a lot of light through.

Sensor size:Large 1.55μm pixels-smaller pixels means higher clarity

Geo-tagging:You can add geographical identification metadata to photographs.

Secondary camera:8 MP, f/2.4 Aperture,Sensor size: 1.4 µm pixel

The first phone with the Google Assistant built in.

What is Google Assistant?-Google Assistant is Google's latest virtual assistant.It is designed to be personal voice assistant.

Here's how Google explains its new assistant:

"The assistant is conversational - an ongoing two-way dialogue between you and Google that understands your world and helps you get things done. It makes it easy to buy movie tickets while on the go, to find that perfect restaurant for your family to grab a quick bite before the movie starts, and then help you navigate to the theater."

How google assistant works

Google Assistant is designed to be conversational. That means you can ask a question and then ask several follow-up questions, and Google Assistant will be able to keep track of the conversation, determine context, and audibly respond with the right information.

For example, you can ask what you should have for dinner, and Google Assistant will locate local places to eat and serve up suggestions, with cards for a selection of restaurants.

Here's how Google Assistant works across the different Google devices.

Unlimited storage for all your photos and videos.

Anyone can download and install Google Photos on their iOS or Android phone. But the photo storage service caps photo resolution at 16 megapixels and video resolution at full HD (1,920 x 1,080) if you want to store an unlimited amount of media for free.

This means if you want to store higher resolution photos and videos at greater resolution (like 4K), you'd need to pay for a monthly storage plan.

With unlimited photo and video storage and their highest resolutions, the Pixel phones are an attractive value for people who want to store their memories in full forever.

Switching

It’s easier than ever to switch.

Switching enables you to transfer data from your existing phone to google pixel

Connect your old iPhone or Android device to your new Pixel with the Quick Switch Adapter.Switching from iPhone, Sign in to your Google Account. If you don't already have one, you'll be asked to create one.

Switching from Android,then your new Pixel should automatically sign you in to your Google Account, but if not, simply enter your password.

Once you’ve signed in to your Google Account, choose what you want to move, like your contacts, calendar events, photos, videos, music, SMS messages, iMessages and more. Then sit back and let Pixel do the work.

Supported devices include:

• iPhone or iPad running iOS 8 and up
• Nexus 5, 6, 5X, 6P running Android 5.0 and up
• Most Android devices running Android 5.0 and up

AMOLED capacitive Multi-touch Display

AMOLED (active-matrix organic light-emitting diode):The key component in an LED display types is a Light Emitting Diode (LED)the key component in these display types is a Light Emitting Diode (LED). In an LED display panel these are shrunk down dramatically and arranged in red, green and blue clusters to create an individual pixel that can reproduce white light and various colors.

Layers of an AMOLED display

The O in OLED stands for organic.There are a series of thin organic material films placed between two conductors in each LED, which is then used to produce light when a current is applied.AM part in AMOLED stands in for Active Matrix, rather than a passive matrix technology.In a passive matrix, a complex grid system is used to control individual pixels, where integrated circuits control a charge sent down each column or row. But this is rather slow and can be imprecise. Active Matrix systems attach a thin film transistor (TFT) and capacitor to each LED. This way, when a row and column is activated to access a pixel, the capacitor at the correct pixel can retain its charge in between refresh cycles, allowing for faster and more precise control.The major benefits from OLED type displays comes from the high level of control that can be exerted over each pixel. Pixels can be switched completely off, allowing for deep blacks and a high contrast ratio. Being able to dim and turn off individual pixels also saves on power. The lack of other layers on top of the LEDs means that the maximum amount of light reaches the display surface, resulting in brighter images with better viewing angles.

In super AMOLED display,it incorporates the capacitive touchscreen right into the display, instead of it being a separate layer on top of the display. This makes the display thinner.

16M colors:Pixel supports True color 24-bit representation or for a total of 224 or 16,777,216 color variations.

Resolution 1440 x 2560 pixels (~534 ppi pixel density):Pixel density (PPI) Refers to the concentration of pixels on a particular display, measured in pixels per inch (ppi). Pixel density is calculated by dividing the diagonal pixel resolution of a display by its diagonal size.
Multitouch:Multi-touch is a method of input on a touchscreen that allows two or more fingers to be used on the screen at one time.
Protection Corning Gorilla Glass 4:This prevents possible scratches.

How Virtual Reality (VR) works?

VR Technology :An overview

Leading VR enabled head mounted display (HMD)

Virtual reality (VR) typically refers to computer technologies that use softwares and hardwares to generate realistic images, sounds and other sensations that replicate a real environment, and simulate a user's physical presence in this environment, by enabling the user to interact with this space and any objects depicted therein using specialized display screens or projectors and other devices. In this article I would like to explore “how Virtual Reality works” and what is the basic principles behind virtual reality.

Nowonly most of us are hearing about VR, but humans have identified Virtual Reality long before. Early versions of VR originated around 1930-40. The first references to the concept of virtual reality came from science fiction. Stanley G. Weinbaum's 1935 short story "Pygmalion's Spectacles" describes a goggle-based virtual reality system with holographic recording of fictional experiences, including smell and touch.After the invention of ‘motion pictures’ ,human’s thrive to experience real world virtually resulted in the invention of various Virtual Reality(VR) equipments. 

For the present generation VR is nothing but google cardboard or Oculus rift head-mounted display or HMD. HMDs typically take the form of head-mounted goggles with a screen in front of the eyes. Some simulations include additional sensory information and provide sounds through speakers or headphones. 

Many of us might have used a VR HMD equipment. How many of us know the simple principle behind this? So, let us have a look at “how does VR work”

Working of a Virtual Reality goggles (head mounted display -HMD)

Virtual reality glasses or goggles are becoming increasingly popular in the gaming and entertainment arena. They are lighter and more comfortable to wear than the standard head mounted display (HMD). Ordinary glasses show a single image but 3D and virtual reality glasses contain polarised lenses which show two images, one per each eye. These images appear to give an illusion of depth of object we see.

The basic principle behind 3D and virtual reality is stereoscopy. Two separate images are shown to each eye, which the brain combines into a single image. We are tricking our brain to perceive two slightly different images as a single image.

Snapshot of a VR Video  frame

Image given above is a snap of 3D VR video. Two images are combined to from a single frame. If you closely observe ,you can see there is slight difference in left and right images. Two slightly different angles of the scene is fed into each eye, simulating depth. This along with other ways to simulate depth like parallax (farther objects to you seem to move slower), shading and techniques create an almost a real world experience. 

360 degree videos

360 videos, also known as immersive videos or 360 degree videos, are videos recording of a real world panorama, where the view in every direction is recorded at the same time, shot using an omnidirectional camera or a collection of cameras. If 360 degree videos are played on your PC screen you can navigate through video using mouse or navigation keys. Using a wearable VR HMD ,You can watch different portions of video as you turn your head around which make it feel more immersive. Your head movement is detected using the gyro sensors on your smart phones. Along with 3D effect, 360 degree view will enhance Virtual Reality effect.

Now,different kinds of wearable VR equipments(HMDs) are available in the market.Google cardboard,Oculs rift,HTC vive and Samsung gear are the major players in the wearable VR HMD market.Google card board is the chepest one,but if you are looking for a real VR experience, go for Oculus rift or HTC vivo.Using a poorly aligned VR product may cause health problems like motion sickness.

Suggested Reading

• Augmented Reality: What is it and How does it works?

Speciality of IPS LCD displays

IPS LCD Display is one of leading display technology used in smartphones and other handheld devices.

Many Leading Mobile Phones like

iPhone7 use an IPS display

Content Highlights

• What is LCD and How it works 
• How LCD panel is wired 
• Twisted nematic LCD 
• Different Layers of LCD pannel
• TFT display and its shortcomings 
• IPS Display technology 
• Advantages and Disadvantages of IPS LCD display technology in comparison with TFT,LED etc..

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Before going into IPS LCD displays,let us have look at basic operation of LCDs. Liquid crystals (LCs) are matter in a state which has properties between those of conventional liquids and those of solid crystals. For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. When electricity is passed through, this crystals scatter light is different directions. This basic property of Liquid Crystals is exploited in Liquid Crystal Displays.

Basic unit of a LCD display system is a liquid crystal cell consists of a thin layer (about 10 u m) of a liquid crystal sandwiched between two glass sheets with transparent electrodes deposited on their inside faces. With both glass sheets transparent, the cell is known as transmittive type cell. When one glass is transparent and the other has a reflective coating, the cell is called reflective type. The LCD does not produce any light of its own. It depends entirely on light falling on it from an external source for producing viewable light.

Twisted nematic LCD

A nematic liquid crystal is a transparent or translucent liquid that causes the polarization of light waves(focusing of light in a plane) to change as the light pass through it.The extend of polarization depends on the intensity of applied electric field.

Twisted Nematics, a particular nematic substance is twisted naturally. When a known voltage is applied to the substance, it gets untwisted in varying degrees according to our requirement. This in turn is useful in controlling the passage of light. The relatively inexpensive twisted nematic display is the most common consumer display type.

Different Layers of an LCD unit

An LCD unit has two polarized glass pieces(F). The glass which does not have a polarized film on it must be rubbed with a special polymer to form microscopic grooves in the surface(B&E). Grooves are on the same direction as the polarizing film. Nematic crystal layer(D) is sandwiched between electrodes. The grooves will cause the first layer of molecules to align with the filter’s(polarizer) orientation. Two grooved glasses are at right angle to each other. Till the uppermost layer is at a 90-degree angle to the bottom, each successive layer of TN molecules will keep on twisting. The first filter will naturally be polarized as the light strikes it at the beginning. Thus the light passes through each layer and is guided on to the next with the help of molecules. When this happens, the molecules tend to change the plane of vibration of the light to match their own angle. When the light reaches the far side of the liquid crystal substance, it vibrates at the same angle as the final layer of molecules. The light is only allowed an entrance if the second polarized glass filter is same as the final layer. Take a look at the figure given above. Please note two polarizers are at right angle to each other.

The main principle behind liquid crystal molecules is that when an electric field is applied across them, they tend to untwist. This causes a change in the light angle passing through them. This causes a change in the angle of the top polarizing filter with respect to it. So little light is allowed to pass through that particular area of LCD. Thus that area becomes darker comparing to others.

Colour LCDs are those that can display pictures in colours. In addition to above layers, there must be three sub-pixels with red, green and blue colour filters to create each colour pixel.

LCD panel wiring

The liquid crystal displays used in calculators and other devices with similarly simple displays have direct-driven image elements, and therefore a voltage can be easily applied across just one segment of these types of displays without interfering with the other segments.

Direct driven LCD pannel

This would be impractical for a large display, because it would have a large number of (color) picture elements (pixels), and thus it would require millions of connections, both top and bottom for each one of the three colors (red, green and blue) of every pixel. To avoid this issue, the pixels are addressed in rows and columns, reducing the connection count from millions down to thousands. The column and row wires attach to transistor switches, one for each pixel. The one-way current passing characteristic of the transistor prevents the charge that is being applied to each pixel from being drained between refreshes to a display's image. Each pixel is a small capacitor with a layer of insulating liquid crystal sandwiched between transparent conductive layers.

TFT Displays

TFT Displays uses TN(Twisted nematic technology) The circuit layout process of a TFT-LCD is same as that explained above. However, rather than fabricating the transistors from silicon, that is formed into a silicon wafer, they are made from a thin film of silicon that is deposited on a glass panel. Transistors take up only a small fraction of the area of each pixel and the rest of the silicon film is etched away to allow light to easily pass through it.

Disadvantage of of TFT displays

Since TFT display uses TN technology,it has got disadvantages of TN displays.TN displays suffer from limited viewing angles. Colors will shift when viewed off-perpendicular

Also, most TN panels represent colors using only six bits per RGB color, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit true-color) that are available from graphics cards. Instead, these panels display interpolated 24-bit color using a method that combines adjacent pixels to simulate the desired shade. This disadvantages lead to the invention of IPS Technology.

IPS Display Technology

IPS (In-Plane Switching) displays provide consistent, accurate color from all viewing angles without blur or grayscale inversion. IPS displays show clear images with stable response time, and no halo effect is produced when touched.

Working of IPS Display

What is an ips display?:Each pixel within an IPS type TFT consists of three sub-pixels (Red, Green and Blue). Each sub-pixel has a pair of electrodes to control the twisting of the Liquid Crystals. Unlike TN type TFTs where the electrodes are on opposing plates, the electrodes in an IPS TFT are on only one of the glass plates (i.e. in the same plane). When voltage is applied to the electrodes, all the Liquid Crystal molecules align in parallel with that plane and allow light to pass through to the polarizers and RGB color filters. In effect, TN displays force the Liquid Crystal molecules perpendicular to the glass which blocks some light from coming out at wide angles, while IPS displays keep the Liquid Crystal molecules in line to allow light through at all angles.

All modern mobiles phones from iPhones,samsung,LG etc.. are using IPS LCD displays.Many varaints of IPS displays are available in market.LG is one of the largest supplier of IPS displays.

Advantages of IPS Display

• IPS panels display consistent, accurate colour from all viewing angles
• Unlike TFT- TN LCDs, IPS panels do not lighten or show tailing when touched (halo effect). This is important for touch-screen devices, such as smartphones and tablets 
• IPS panels offer clear images and stable response time .

Disadvantages of IPS Display

• IPS panels require up to 15% more power than TN panels.
• IPS panels are more expensive to produce than TN panels.
• IPS panels have longer response time than TN panels.

All modern mobiles phones from iPhones,samsung,LG etc.. are using hd ips display.LG is one of the largest supplier of IPS screen displays.Are you planning to buy a IPS display laptop or full HD IPS display smartphone,then do some research ,because many varaints of IPS display monitors are available in market.Choose your product based on the price and affordability.

Suggested Reading

• IPS display vs super amoled
• IPS vs OLED
• micro-LED Displays

Atomic clock -World's most accurate clock-How does it works?

Atomic clock is the most accurate clock:how does an atomic clock work

NIST-F1 would neither gain nor lose one second in about 100 million years

Content Highlights

• Types of clocks and basic principle behind a clock.
• What is a atomic clock?
• Principle behind an atomic clock
• How does an  Atomic Clock works?
• NIST-F1 Cesium Fountain Clock
• Definition of a second
• Applications of atomic clocks

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Before going into the atomic clock, let us see what a clock really is. A clock's job is to measure passage of time. All clocks do this by measuring some sort of resonation of one or another material. Let us have look at some commonly used clocks.

pendulum clock :In a pendulum clock, the resonator is a pendulum and the gears in the clock keep track of time by counting the resonations (swinging) of the pendulum. The pendulum resonates at a frequency of one swing per second.

Digital clock: It either measures oscillations on power line or oscillation provided by an electronics circuit. In US power supply oscillates at 60 cycles per second and in Europe and Asia power supply oscillates at 50 cycles per second.

Quartz clock: In this type of clocks ,on supply of electric current quartz crystal oscillates at a particular frequency. This resonating frequency is converted into measurable form with the help of gears.

What is an atomic clock

the NIST-F1 in Boulder, Colorado

In an atomic clock an ‘atom’ or a ‘molecule’ is the resonator. In every clock accuracy of resonator determines accuracy of time. An atom resonates at extremely consistent frequency. This ensures the accuracy of an atomic clock. In all other clocks resonator is manufactured, so, there is limitation in accuracy that can be obtained from such resonators.

Basic principle behind an atomic clock

When exposed to certain frequencies of radiation, such as radio waves or microwaves the electrons that orbit an atom's nucleus will "jump" back and forth between energy states. The electrons absorb energy to move to a higher energy level (away from the nucleus), and release energy to move down an energy level (towards the nucleus). This “jumping” happens at extremely consistent frequency .Clocks based on this jumping within atoms can therefore provide an extremely precise way to count seconds.

Commonly used atoms in an atomic clock: Currently caesium (³³Cs) is the widely used one,but rubidium (⁸⁷Rb) and thallium (²⁰⁵Tl) were used earlier.

Working of an Atomic clock.

There are many atomic clocks around the world. Out of which, NIST-F1 Cesium Fountain Clock is one among the most accurate clocks.It is developed by National Institute of Standards and Technology (U.S. Department of commerce) . The uncertainty of NIST-F1 is continually improving. As of January 2013, the uncertainty has been reduced to about 3 x 10-16, which means it would neither gain nor lose a second in more than 100 million years .NIST-F1 is referred to as a fountain clock because it uses a fountain-like movement of atoms to measure frequency and time interval.

Diagrammatic representation of a an atomic clock 

Laser cooling: We know that a moving atom possess higher energy than the stationary one. To restrict the movement of cesium atoms a technique called LASER cooling is used in NIST-F1 clock. First, a gas of cesium atoms is introduced into the clock's vacuum chamber. Six infrared laser beams then are directed at right angles to each other at the center of the chamber. The lasers gently push the cesium atoms together into a ball. In the process of creating this ball, the lasers slow down the movement of the atoms . Laser cooling drops the temperature of the atoms to a few millionths of a degree above absolute zero, and reduces their thermal velocity to a few centimeters per second

laser cooling-atoms are stabilized

using six laser beams 

Two vertical lasers are used to gently toss the ball upward (the "fountain" action), and then all of the lasers are turned off. This little push is just enough to loft the ball about a meter high through a microwave-filled cavity. Under the influence of gravity, the ball then falls back down through the microwave cavity.

a ball of atoms tossed up by
laser beams

when laser is turned off ,atoms fall down
due to gravity

The round trip up and down through the microwave cavity lasts for about 1 second. During the trip, the atomic states of the atoms might or might not be altered as they interact with the microwave signal. When their trip is finished, another laser is pointed at the atoms. Those atoms whose atomic state were altered by the microwave signal emit light (a state known as fluorescence). The photons, or the tiny packets of light that they emit, are measured by a detector.

Detection of photons emitted by caesium atoms

This process is repeated many times while the microwave signal in the cavity is tuned to different frequencies. Eventually, a microwave frequency is found that alters the states of most of the cesium atoms and maximizes their fluorescence. This frequency is the natural resonance frequency of the cesium atom (9,192,631,770 Hz), or the frequency used to define the second.

Definition of a second: According to The International System of Units (SI) "The second is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. This definition refers to a caesium atom at rest at a temperature of 0 K "

Applications of atomic clocks 

What is the need of an atomic clock?..It has got many applications in our life.Some of them are listed below.

1.GPS and similar navigation systems:In GPS our position is calculated based on the time taken by the signal to travel between GPS satellites and receiver. To determine position with high precision even billionths of a second is significant. 

2. Telecommunications systems require synchronization better than 100 billionths of a second .

3. Electrical power companies use synchronized systems to accurately determine the location of faults (for example, lightning damage) when they occur and to control the stability of their distribution systems.

4. In space exploration, radio observations of distant objects in the universe, require exceedingly good atomic reference clocks. And navigation of probes within our solar system depends critically on well-synchronized control stations on earth.

5. The time-related quantity called frequency, basically the rate at which a clock runs, is needed by the radio and television broadcast industry to maintain proper control of transmissions and thus avoid interference between stations.

6.Using the internet every computer can synchronize its time setting with a centralized time server – the atomic clock time server – so that all the computer times all around the world can use standardized settings, even though they are scattered through different time zones. Most operating systems (i.e. Windows, Mac, Linux) have an option to automatically synchronize the system clock periodically using an NTP (network time protocol) server: NIST is offering a network time service to deliver UT1(Universal Time) time.

Still atomic clock researches are going around the globe .And scientists are coming up with more and more accurate atomic clocks.

References:

1. NIST Cesium Fountains — Current Status and Future Prospects S.R. Jefferts∗ , T.P. Heavner, T.E. Parker and J.H. Shirley http://przyrbwn.icm.edu.pl/APP/PDF/112/a112z506.pdf 
2.  https://www.nist.gov