Input Devices Flashcards
Input device
Hardware device, which allows user to enter data into a computer
Hardware
The physical components of a computer
List 5 input devices
1) Keyboard
2) Mouse
3) Scanners (2D/3D)
4) Barcodes
5) QR-codes
How does a physical keyboard work?
When a key is pressed, an electronic signal goes to a computer. The computer processes the input and gives an output
How does a virtual keyboard work? (on mobile)
When the specific areas are pressed the output is triggered
List 2+ and 1- of a keyboard
+ Easy to use
+ No need for specific software and knowledge
- Takes lots of space
Mouse
It controls the pointer on the screen. Usually has 2 buttons and a scroll wheel. Older mice had a roller ball. Now a laser is being used
List 2+ and 1- of a laser mouse
+ Easy to use
+ No need for specific software and knowledge
- Smooth, not glass surface is needed
2D scanners
Used to scan physical documents and convert them into a digital format. The light source moves down the document and the reflection is captured. The captured image reflects onto several mirrors, convert it, send to the computer
List 1+ and 1- of a 2D scanner
+ Good quality image
- Take lots of space
3D scanners
Scan 3D objects, can be printed on a 3D printer. The scanner uses the reflection of the light or the X-rays to create a model
Where can 3D scanners be used? (1)
Airport security
When were barcodes developed?
1970s
Barcode
Illuminates the bars and the reflection is received as analog and converted into digital. Processes by a computer
List 1+ and 1- of a barcode
+ Very efficient way of finding info about the product
- Code damaged or not in the database it wouldn’t be read
QR codes
Can store bigger amount of characters than the barcode. Anyone can make a QR code and scan it
What do the big squares around the QR code tell?
Where the QR ends
List the things a barcode can contain? (5)
1) Text
2) Links
3) Contacts
4) Images
5) SMS or Email
List 3+ and 1- of a QR code
+ If it is slightly damaged, still can be read
+ More efficient in storing data than Barcodes
+ Can be scanned without a database
- Not popular
CAD
Computer aided design
OCR - how?
Optical character recognition, a process where scanned document is recognised and converted to inputs
OMR - how?
Optical mark recognition, a process where scanned marks on a page are automatically converted into inputs
Biometric device
A device, which recognises human physical characteristics
Give examples of a human physical characteristic (3)
1) Finger print
2) Iris
3) DNA
Sensor
Device which recognises physical inputs
Analogue
Signal , or data that constantly varies
Digital
Signal, or data that consists of two state 1s and 0s
Touch screen
Interactive device which combines liquid display LCD with a touch sensitive device
Why a touch wouldn’t be detected by a smartphone by a finger in a glove
A glove doesn’t allow the natural electrical signals that we have in our body to de detected by the sensor
How does the information gets transferred between a computer and a whiteboard
By a HDMI cable
What does a microphone do?
Converts an analogue input into digital
List 2+ and 2- of a digital camera
+ Images can be edited immediately
+ Easy sharing
- Takes lots of memory
- Pixels are in proportion to quality, smaller number of pixels, smaller the quality
List 3+ and 2- of a touch screen
\+ Simple to use \+ Save space \+ Multitouch - Can't be used in gloves - If the screen is damages the touch can;t be used
List 2+ and 1- of an interactive whiteboard
+ Useful for education
+ Large screen
- Must be accurately calibrated, to work properly
List 2+ and 2- of a microphone
+ Disables users can use a microphone to input info
+ Speech recognition
- The sound is not always the best quality
- Speech recognition programs has to be trained
