Chapter 2 - Input and Output Devices

What is a Video Camera?

-A device that captures moving images or videos

Advantages of Optical Character Reader? (OCR)

-A fast way of inputting text that has been printed on paper. -Can avoid typing error.

What are Sensors?

-Are able to measure quantities such as temperature, pressure and amount of light.

What is a Light Pen?

-Are ideal where space is limited and are used an alternative input device to mouse or graphics tablet.

Disadvantages of Microphones?

-Background noises can cause problems with voice recognition system. -Sound files, when stored, take up a lot of disk space

Disadvantages of Bar Code Reader?

-Bar codes can sometimes be damaged. -Only a limited amount of data can be stored in a bar code.

Advantages of Microphone?

-Can be used by disabled to input data/instruct -Very cheap to buy -Can be faster to speak instructions rather than type them

Advantages of Video Cameras?

-Can capture both still and moving images. -Easy to transfer video to the computer -Can store many images/videos until later for editing

Disadvantages of Video Cameras?

-Can erode privacy as CCTV cameras are present in many places. -It is very hard to produce good videos without training. -Expensive to buy

Advantages of Web Cams?

-Can see the reactions or people as you are talking to them -Parents can see their children and grandchildren and speak to them if they do not live near.

Disadvantages of Sensors?

-Cost to purchase -Dirt and grease may affect performance.

What is a Web Cam

-Digital cameras that can take both still and video images which can be transferred to other computer or saved.

Advantages of Light Pen?

-Enable users to draw directly on the screen -Useful where there is no space to use a mouse or graphics tablet.

Advantages of Bar Code Reader?

-Faster than typing in the number? -Greater accuracy -Can be read fro a distance

What are Graphic Tablets?

-Is a flat board which you use to draw or write on using a pen-like device called a stylus

Disadvantages of Web Cams?

-Limited extra features to improve image quality. -Picture quality can be poor at low resolution -Generally have a fixed position so do not move ground

Advantages of Optical Mark Reader? (OMR)

-Only need one computer and optical mark reader to read marked sheets. -Fast at reading the forms and analysing the results.

Disadvantages of Optical Mark Reader? (OMR)

-Only suitable for capturing certain data - data needs to be in a for where are tick-style answer. -If the form used is creased or folded it may be rejected or jam the machine.

Advantages of Sensors?

-Readings are more accurate then those taken by human -Can work in dangerous environments (e.g. mines or nuclear reactors.)

What is a Bar Code Reader?

-Series of light and dark bars of different widths. -Use to input the number using a bar code reader

Disadvantages of Graphic Tablets?

-Specialist tablets are expensive

Disadvantages of Optical Character Reader? (OCR)

-Text needs to be clearly typed or written -The forms may be rejected if they are incorrectly filled in.

What is an Optical Mark Reader? (OMR)

-Use paper-based forms or cards with them which are read automatically by the device. -Used to assess customer satisfaction with a product or service.

Advantages of Graphic Tablets?

-Used in countries such as Japan and China where graphical characters are used instead of letter for words. -It is more accurate to draw freehand on a table rather than use the mouse use to draw.

What is an Optical Character Reader? (OCR)

-Works by scanning an image of the text and then using special recognition software to recognise each individual character

Chapter 2 - Input and Output Devices

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Digital Cameras

A device to store digital photographs on a memory card.

Scanners

A device used to convert images or text on paper into a digital format that can be used by the computer

Microphones

A device used to input sound

PIN pads

A device with a numeric keypad used to enter a person's Personal Identity Number

Mouse

A pointing device used to control a pointer or cursor.

Touchpads

An input device which is usually found on a laptop computer

Disadvantages of Remote Control

Batteries need constant replacement in order for it to operate.

Advantages of keyboards

Can enter data quickly

Touch Screen

Device which works as both input and an output device.

Chip Readers

Devices which is used to place a credit/debit card to read the data on the card

Advantages of Remote Control

Easier to control from a distant as it can operate a device wirelessly.

Advantages of Touch Screens

Easier to use as software can alter the screen while it being used.

Disadvantages of keyboards

Easy to make mistakes when typing data

Disadvantages of using Mouse

Excessive use can lead to health problems such as repetitive strain injuries

Remote controls

Hand-held device which is used to control a machine from a short distance away

Magnetic Stripe Reader

Hold personal details such as account details such as account number and name.

Advantages of using Mouse

Ideal for use with desktop computers

Joystick

Input device which is mostly used for playing computer games such as flight stimulator.

Numeric Keypad

Keypad consists of the numbers 0 to 9 along with an 'Enter' and 'Cancel'

Keyboards

Made of button called 'keys' used to enter letters

Advantages of Digital Cameras

No film to develop so quicker to produce photos

Disadvantages of Magnetic Stripe Readers?

Not always secure as thieves can obtain the readers and read the data on the card

Disadvantages of Touch Screens

Not suitable for inputting large amounts of data

Disadvantages of Numeric Keypad

Only allows numeric data to be entered which limits the usability.

Disadvantages of Digital Cameras

Photographs may not be as high quality as those produced using film

Input Devices

Piece of hardware that is used to enter the data into a computer

Advantages of Joystick

Provides a better gaming experience for racing or flying styles of computer games

Advantages of numeric keypad

Rapid operation for experienced users

Advantages of Magnetic Stripe Reader

Simpler to use for people as it does not require any training

Disadvantages of Joystick

Some people find joysticks more difficult to control than a tradition mouse.

Disadvantages of Touchpads

Takes practice and skill to control the position of then cursor using the touchpad.

Disadvantages of Scanners

The quality of the final image is dependent on the quality of the original image

Advantages of Touchpads

Useful for laptops when using a mouse isn't practical

Advantages of Scanners

Very accurate and can product reasonably high quality images