Smartphones have already gone mainstream and naturally blended into daily life, and alongside that, all sorts of attempts at using them 'smartly' are happening — and a fair number of them have actually made real progress.
Especially when you look at today's smartphone apps, there are plenty that are both imaginative and useful in ways nobody would have expected — and that is possible because apps tap into the various sensors packed into the phone.
A sensor, also called a 'detector', is a component that converts temperature, light, sound, pressure and so on into a standardized signal. Put simply, it mechanizes or electronicizes the five senses humans have — for example, the camera on a smartphone stands in for sight, the microphone for hearing, the touchscreen for touch. GPS tells you objective location, and the accelerometer and gyroscope give it a sense of balance.
The various sensors provided in the Optimus LTE2
Especially when these sensors are hooked up to a computer and connected to the internet, they unlock astonishing possibilities nobody had imagined. Layer a little creativity on top of freely developable apps, and things that felt like pure imagination suddenly become possible.
For that reason it's worth looking at the sensor technology at the root of it all — by going through the technology level of each sensor currently developed and fitted into smartphones, along with the apps that use them, we can get a sense of how they might change our lives going forward.
Does a smartphone have eyes too? Image sensor, illuminance sensor
At some point, taking photos with a smartphone became a basic feature, and lately it has settled in as one of the criteria when choosing a phone.
The reason you can take pictures with a smartphone is entirely thanks to the image sensor. In the past, because it had to fit into a small smartphone, the image sensor inevitably had to be small, so there was a big gap between it and the image sensor of a regular digital camera — and that gap was clearly visible in actual photo quality and features.
For reference, the image sensor in an entry-level 'point-and-shoot' camera is 1/2.3 inches, the image sensor in the recently released iPhone 5S is estimated at 1/2.8 inches, and the Galaxy S4 uses a 1/3.06-inch image sensor.
But image sensors in smartphones have kept improving, and now they can produce photos every bit as sharp as a decent digital camera — and with things like the G2 with optical image stabilization, or the Nokia 808 PureView with its 41-megapixel sensor, all kinds of experiments are going on.
Besides the image sensor, the illuminance sensor — sometimes called a light sensor — also plays the role of a smartphone's eye. It measures the amount of surrounding light and uses that to adjust the LCD backlight according to ambient brightness.
In other words, if you set the screen brightness to 'auto', the screen automatically dims a little in dark places and brightens up in bright places so it's still readable, minimizing unnecessary battery drain and improving readability.
One app that uses the illuminance sensor is Pocketmode, which automatically adjusts ringtone volume based on the sensor's reading.
For example, if you put your phone in your pocket or bag, it senses the darkness and raises the ringtone so you can find it easily, and when you take it out, the volume returns to normal automatically.
It works for text messages too, and since illuminance sensors often don't work properly at night, there's also a night mode so the app doesn't activate during a user-specified time window.
Sensing touches on the smartphone — touch sensor, fingerprint sensor, proximity sensor
We use touch dozens — no, maybe hundreds — of times a day to operate our smartphones. This, too, uses a sensor, and touchscreens are now embedded in everything that has worked its way deep into daily life — smartphones, tablets, even car controls and bank ATMs.
When touch phones first came out, pressure-based resistive touch panels were the norm, but they generally had poor screen clarity, were weak to impact, and were awkward with finger input because their sensitivity was too low for fine gestures — so capacitive touchscreens are mostly used now.
Capacitive (or capacitance-based) touch uses the static electricity in our bodies, so input works with a light touch on the screen, and it supports multi-touch, which enabled pinch-to-zoom and various motions. It also supports high image quality and high resolution, enables smooth input, and allows much more intuitive operation — all of which play a fundamental and important role in today's smartphones.
LG Electronics' Zero-Gap Touch, a fully cover-glass-integrated touch technology
As the performance competition among smartphone makers heats up, competition over the latest touch technology — not just high resolution — is getting fierce.
New touch technologies not only help improve touch responsiveness and resolution, but also make the phone thinner and lighter. Apple's In-Cell, Samsung's On-Cell, and LG's Zero-Gap Touch have each been applied to their flagship smartphones.
Lately there are attempts to grab both rabbits — security and convenience — by fitting smartphones with a fingerprint sensor. Not long ago Apple unveiled a security system on its flagship iPhone 5S using a fingerprint sensor (Touch ID), and other smartphone makers are competing to launch or prepare products with fingerprint features.
Fingerprint recognition is largely split into Area and Swipe methods. Apple went with the area method, where simply placing a finger reads the print. Android tends to use the swipe method, where you drag your finger over the sensor to input the fingerprint.
The iPhone 5S has Touch ID with fingerprint recognition built into the home button.
The defining feature of the iPhone 5S is that the fingerprint sensor is built into the home button.
Placing a finger on the home button enters fingerprint mode and unlocks the phone, and it is expected to expand into things like payment systems. Because the sensor recognizes the fingerprint regardless of finger direction, and the resolution and recognition rate are very high, it is praised for improving user convenience compared to previous fingerprint-equipped smartphones.
The Vega LTE-A offers a 'Secret Key' on the back that combines a touch sensor and fingerprint recognition.
In Korea, Pantech's 'Vega LTE-A' drew attention as the first LTE-A smartphone to include a fingerprint feature, called the 'Secret Key'.
Pantech's 'Vega LTE-A' fingerprint button sits on the back so you can comfortably use it in one hand, and the back touch lets you control most smartphone functions while also providing fingerprint-based security.
The proximity sensor built into a smartphone uses electromagnetic force without physical contact to detect whether an object is present, passing through, flowing continuously, or piling up, and it is used for sensing and position control — it detects whether objects are nearby and triggers various actions accordingly.
The proximity sensor actually works every time we make a call — when you bring the phone up to your ear after placing a call, the screen turns off by itself. That is the smartphone using the proximity sensor to recognize that the phone and your face have come close, and automatically turning the screen off. This prevents unintended touches during a call and also saves battery.
A Pantech commercial that showed a great example of motion recognition in use
Of course, the screen turning back on when you look at the phone during a call is the same mechanism, and recently various applications of the proximity sensor have been tried — muting sound by flipping the phone over, or answering calls and flipping pages with a hand gesture alone.
The smartphone tells you where you are — GPS sensor, geomagnetic sensor
Smartphones can play the role of a navigation device solidly thanks to the GPS sensor. GPS is short for Global Positioning System, and it calculates timing differences between multiple GPS satellites orbiting Earth to identify current location. Through the GPS sensor you can know the smartphone's current location and time, and use that for location-based services and many other services.
Alongside it, the geomagnetic sensor detects azimuth using Earth's magnetic field. It's mainly used to realize digital compass features and, combined with GPS, to implement location-based services (LBS).
The metal detector in Smart Tools — as you get closer to metal, the magnetic field reading goes up.
The geomagnetic sensor is applied to maps for accurate direction, and is used widely not just in mobile phones but in radios, GPS, PDAs, and navigation devices. It also has metal-detection capability, so it's used in metal-detection software too.
Sensing the smartphone's precise movement — gravity sensor, accelerometer, gyro sensor
To precisely grasp a smartphone's movement you need a gravity sensor, accelerometer, and gyro sensor. The gravity sensor tells whether the phone is in landscape or portrait and adjusts the screen accordingly; the accelerometer senses changes in speed or impact; and the gyro sensor detects the device's rotation along three axes to register tilt.
The gravity sensor — also called a G-sensor — senses Earth's gravity as the name suggests, detecting which direction gravity is acting in, and provides user-convenience features adapted to that state. Lately, more and more digital devices are packing in gravity sensors, widening their applications.
Simply put, the gravity sensor lets the smartphone tell where it is on Earth and which way is up or down, so when we use a phone's auto-rotate, the screen adjusts automatically based on whether the device is landscape or portrait — because the gravity sensor reads the screen state and position.
Beyond that, location-based services like ScanSearch, iNeedCoffee, and Odiyar become possible, and because motion itself can be recognized without button presses, you can enjoy lively experience-based games.
Sleep Cycle, which uses the gravity sensor to analyze sleep patterns
For example, a sleep-tracking app called Sleep Cycle uses the gravity sensor to detect tossing and turning during sleep, builds a sleep cycle chart, and — if you set an alarm time — wakes you up during a light-sleep window around that time when you're easiest to wake.
The accelerometer measures the acceleration and impact force of a moving object.
It processes output signals to measure dynamic forces — acceleration, vibration, impact — and can sense an object's state of motion in detail, so its uses are very broad and varied.
Accelerometers are essential for control systems in all kinds of vehicles (cars, trains, ships, airplanes), in factory automation and robotics. The easiest way to experience an accelerometer is in any navigation app — for cars or sports — and especially apps that record running or cycling, where simple speed-based sensors aren't enough.
The gyro sensor — also known as a gyroscope sensor — adds rotation on each axis to the existing accelerometer, enabling recognition of six axes in total and thus more precise motion detection. An accelerometer simply detects acceleration and deceleration along three axes, while a gyroscope can directly detect height, rotation, and tilt.
In particular, the iPhone 4 combines the existing three-axis accelerometer with a newly added gyroscope sensor to enable precise six-axis motion sensing. That allows fine-grained, accurate controls just by moving the phone — no screen dragging needed — and is expected to be used not only in games but also in various fields including mobile augmented reality.
A game that takes advantage of the gyroscope
The gyro sensor provides the location information needed for augmented reality.
Of course, various AR features using accelerometer, geomagnetic sensor, GPS, and location information already existed on smartphones. But with those technologies, it was hard to show accurate location info aligned with where the user was actually looking.
For example, when a user runs an AR app and points the camera at a restaurant, the app is supposed to overlay the restaurant's menu and user reviews — but in practice accuracy suffers so much that the menu often pops up over the clothing store next door. Move the screen around and the displayed info lags and floats over the screen.
With A-GPS, which improves GPS accuracy, being added to recent smartphones, and a gyroscope sensor on top of that, much more accurate overlays can be placed on the screen. Beyond the location-based AR above, marker-recognition and image-processing-based AR can also achieve a much higher level of polish.
For reference, motion-recognition sensors are getting attention lately. Also called Motion Recognition Sensors, they recognize an object's motion or position, and are composite sensors that combine a geomagnetic sensor, accelerometer, altimeter, gyro, and more into a single chip.
These enable compasses, pedometers, navigation features — and also things like locating people in fires or emergencies, or 3D games played through the phone's motion.
Smartphone sensors substituting for the human five senses — but first we must prepare for the risks.
So far we've looked briefly at major smartphone sensors, their roles, and how they're used. Through them, we can see increasingly diverse mobile content being created and evolving, very close to our daily lives.
For reference, beyond the sensors we covered, many more are being developed and applied to smartphones.
For example, a Barometer detects the air pressure of your current location and — by measuring pressure differences — calculates slopes, so it can accurately measure calories burned when climbing a mountain or going up and down stairs. An RGB Sensor measures light intensity and adjusts screen brightness, reducing eye strain when you read an e-book or use various apps. A temperature/humidity sensor can measure ambient temperature and humidity and visually show you the most comfortable environment to live in.
Smartphones will surely expand further into sensors that recognize physical information, user behavior, and emotions. For instance, Microsoft is reportedly developing a MoodScope sensor that detects the phone owner's mood — tension, stress, happiness, excitement, anger, boredom, and so on.
Just as we use our eyes, nose, and mouth to assess a situation now, smartphone sensors will eventually take over these tasks, so dependence on sensors is bound to grow.
As sensor precision rises and application scope widens, collected data grows exponentially — so how we turn it into databases, analyze it, and extract accurate data to drive action all matter, but so does the rising risk when the related information is misused. That's why thorough user opt-in options and security for such sensors must come first.
Editorial / press@bodnara.co.kr
[Related articles]
Differences between free mobile security vaccines by function
The best-value KitKat reference phone, Google Nexus 5
Urgent preview of the Google Nexus 5 launched on the 1st
A winning move in phablet competition — LG Vu3 with a stowable pen and 4:3 screen
Same exterior but a perfect upgrade — Apple iPhone 5S
|
Bodnara's articles can be used at the original source under the Attribution-NonCommercial-NoDerivs 2.0 Korea license. Copyright (c) NexGen Research Inc. Bodnara Go to original source |
