Input

Question 1

What do input devices do?

Answer 1

Transfer data form the source in the outside world to the computer.

Question 2

What are some examples of input devices?

Answer 2

• Keyboards
• Microphones
• Touch Screens

Question 3

What are 2D scanners used for?

Answer 3

Convert a hard copy document or photograph into a computer readable format.

Question 4

What is a sensor?

Answer 4

A hardware device that can take measurement of physical properties, such as temperature or pressure from real world surroundings, these measurements are a representation of the actual property being measured.

Question 5

What are bar-codes used for?

Answer 5

Identification

Question 6

What are the two types of bar code?

Answer 6

• Linear Barcode

* Quick Response code QR

Question 7

How do pen type readers work?

Answer 7

• A light source and a photo diode are placed together in the tip of a pen to read a bar-code, the tip of the pen is dragged across the bars at an even speed.
• The photo diode measures the intensity of the light reflected back from the light source and generates a waveform that is used to measure the widths of the bars and spaces in the barcode.

Question 8

What are the four types of barcode reader?

Answer 8

• Camera based readers
• Digital Cameras
• Laser Scanners
• Pen Type Readers

Question 9

How do laser scanners work?

Answer 9

Similarly to pen type readers, except a laser is used.

Question 10

How does a camera based imaging scanner work?

Answer 10

It uses a camera and image processing techniques to decode a 1D or 2D bar code

Question 11

WHat are some of the advantages to using an imaging scanner?

Answer 11

They can read a barcode on any surface, printed or onscreen and can also read a code that is damaged or poorly printed.

Question 12

How does a digital camera work?

Answer 12

• A digital camera uses a CCD or CMOS sensor comprised of millions of tiny light sensors arranged in a grid.
• The binary data from each sensor is recorded onto the camera’s memory card so that the image can be reprodued using suitable software at a computer.

Question 13

What are some advantages to using digital cameras?

Answer 13

• A CCD sensor tends to produce higher quality images and they are used in higher end cameras.
• They are more reliable, since they have been around for longer than others.

Question 14

What does and RFID chip consist of?

Answer 14

• A small microchip transponder

* Antennae

Question 15

What are active tags?

Answer 15

• Physically larger than passive, because they require a battery to power the tag so that it actively transmits a signal for a reader to pick u.

Question 16

What are passive tags?

Answer 16

• Cheaper to produce
• They do not have a battery, they rely on the radio waves emitted from a reader up to a meter away to provide sufficient electromagnetic power to the card using its coiled antenna.
• Once energized, the the transponder inside the RFID tag can send its data to the reader nearby.