Chapter Two: Input Devices Flashcards
What is a scanner
Scanners are machines used to enter information from a hard copy like documents or photographs
Advantages of scanner
Images can be stored for editing at a later date
Possible to recover damaged documents or photographs by scanning and using a software to fix it
Disadvantages of scanners
Quality can be limited depending on the scanner
They can be fairly slow at scanning
What are the advantages of digital cameras
They take better photographs than smartphones due to better lenses and dedicated software
Easier and faster to upload photographs to a computer than scan it in hard copies
Memory card and store many photographs
What is a sensor?
A sensor is a device that inputs data which is a measurement of a physical quantity which changes like temperature to a computer.
What is an ADC?
An analogue to digital converter (ADC) converts the analogue data to digital data which a computer can understand
What are direct data entry devices?
These devices are used to input data into a computer without the need for much human interaction. For example a barcode reader
What is a RFID and RFID reader
Radio frequency identification readers use radio waves to read and capture information stored on a tag
Where are RFID used?
Retail like warehouses
Libraries
Admission passes
Advantages of RFID
It is very robust
No line-of-sight contact is needed and can be read from a distance
Can detect and read multiple tags at the same time
Disadvantages of RFID
Tag collision could occur as waves could interfere
It is expensive
It is easy to jam or hack
What is an LCD screen?
And LED screen is made of tiny light emitting diodes. Each LED is either red, green or blue in colour.
What is an LCD screen?
LCD screens are made up of tiny liquid crystals. These tiny crystals make up an array of pixels which are affected by changes in applied electric fields
What is an actuator?
An actuator is a mechanical device that is used to control devices such as motors, pumps etc
