S15 - Mobile Devices Flashcards
Smartphones & tablets are considered mainly as
Consumption devices as the goal is to consume information and typically not generate
Name the two types of touch-screen
capacitive, multi-touch
Define capacitive touch screen
Any touchscreen that works by seeing the distortion in an electrostatic field, cheaper & single tactile (1 input at a time)
define multi-touch touchscreen
Can process 2 or more contact point simultaneously, more expensive & very common
What types of displays exist
LCD, LED, OLED
Define Liquid-Crystal-Display (LCD)
Uses liquid crystal where the properties can changes the application of the voltage
Define Pixel (picture element)
Individual point on a screen inside of a display
What are we talking about when mentioning A thin-film transistor (TFT)
the LCD panel
3 types of TFT
Twisted Nematic (TN), In-plan switching (IPS), Vertical alignment (VA)
Define twisted nematic (TN)
contains crystals that twist or untwist in response to the voltage being applied or removed, earliest type of TFT & fast response time
Define In-plane switching (IPS)
Uses crystals that rotate to be able to deliver colour, better colour display from different angles & 178degree horizontal and vertical viewing angles
What is more commonly used Twisted Nematic or In-Plane switching and why
In-Plane switching as it allows for similar speeds to TN however as the crystals rotate instead of twist, this means that viewing angles are improved and you don’t need to see the display face on
Define Vertical Alignment (VA)
Crystals are tilted to be able to deliver colour, has contrast ratio x2-3 compared to IPS but viewing angles and reaction times are worse
Define cold cathode fluorescent lamp (CCFL)
Lamp that sites behind the display and lights up the liquid crystal display to show the colours and images properly on the screen
What does CCFL require for power
Converting of power from battery to AC voltage
Define light-emitting diode (LED)
Newer form of light that uses direct current (DC), less power usage and better performance
Define organic LED (OLED)
Each pixel as its own separate LED that provides the light, can be made from plastic rather than glass meaning they can be folded, manipulated
Drawbacks of OLED
Low maximum brightness, susceptible to burn in (Same image being on display for hours, consequently being burnt into the OLEDs)
Define digitizer
Layer sandwiched between a layer of protective glass and the display panel inside the touchscreen display, provide haptic feedback (e.g. little vibration)
Define accelerometer
combination device that uses hardware and software to measure the velocity, rotation and shaking of a mobile device.
What are 2 purposes of the accelerometer
Screen orientation for phones - knowing when to change from vertical to horizontal, Used for gaming for e.g. car games where you need to turn the device to create a turn left or right input
Define gyroscope
An improved version of the accelerometer, allows for x, y, z instead of just x and y. horizontal, vertical, depth axis
Define track pad
device that can be used to manipulate the cursor across the screen. Type types: embedded & external
Define drawing pad
Large format touch device attached as a peripheral to a laptop, tablet, smartphone or tablet. Uses a touch pen
Define microphone
Any device used to record audio or capture voice when making a phone call
Define speaker
allows to hear things that are coming out from devices, such as music or videos
Define headset
Combines both mic and speaker into one device
Define digital camera
Provides the ability to capture a live image in a still format
Define cellular
Network that allows to connect to the internet using cellular radio inside the handset and connect to a network service provider
What are the two main cellular technologies
GSM or CDMA (based on which area of the world you’re living in + network provider)
Define Global system for mobile communication (GSM)
Cellular technology that takes the voice during a call and converts it into a digital format
Define Code-division multiple access (CDMA)
cellular technology that uses code division to split up the channel
Compare CDMA and GSM
CDMA is more power and flexible compared to GSM
Define Sim card
how you identify yourself to a network in a GSM network
define electronic code
Used by CDMA, allows for electronic changing of SIM and is a cheaper way of getting data service overseas
Define preferred roaming list (PRL)
Contains al the information about different cellular towers
Define bluetooth
uses a short range point to point connection between a mobile device and an accessory
Define universal asynchronous receiver-transmitter (UART)
Device that allows to connect to a device and get information about it
Define port replicator
uses the exact same features as a laptop, beneficial for saving time e.g. (plug all cables into the replicator and then just plug in the single for the laptop) MAKES LIFE EASIER
Define docking station
Advanced type of port replicator that provides all the capabilities and features of a laptop + extra (some contain HDDs, ports that don’t already exist)
port replicator and docking station simplification (2 words each)
PR: port mirror
DS: additional ports
