Fundamentals of Hardware and Software

OUTPUT DEVICES AND MEDIAS

Output

This refers to the results of the computer’s processing operations, which transform unorganised or disorganized data into useful form. This is when data is transferred from Primary Memory (and Secondary Storage) to an Output Device.

Output Media

Output Media's are the means by which information (processed data) is recorded, printed out or displayed for future use.

Types of Output

Audible/Voice Output

This occurs when information is outputted in the form of voice. This type of output consists of sounds, music, or synthesized speech. Please note that sounds cannot be classified as output unless they have been processed.

Video Output

This kind of output consists of a series of still images that are played back at a fast enough Frame Rate to give illusion of continuous motion. Frame Rate refers to the number of images displayed per second.

Audio Output

This is an output that emerges/comes out as sound rather than a visual output.

Computer Output on Microfilm (C.O.M)

This is when pages to be printed are photographically reduced and produced on microfilm (just like those used to display negatives of pictures taken by a camera).

Soft Copy/Temporary Copy

This is computer output on a soft (intangible) medium, which can be seen, (heard) and not touched. E.g. output displayed on the Monitor (Visual Display Unit - VDU) or in the form of sound.

Hard Copy/Permanent Copy

This is computer output on a hard (tangible) medium, which can be seen and touched. E.g. output printed on paper or displayed on microfilm. Normally consisting of characters – letters, numbers, and punctuation marks), a list of names, address or a document that has been formatted for attractive printing. Graphics Output may also be a form of Hard Copy Output consists of visual images including charts, pictures, etc. Please note that Graphics Output isn’t output unless it has been processed in some way.

Human Readable Copy

This is when information is printed on a hard (tangible) medium that enables the user to read from it.

Machine Readable Copy

This refers to information that can be read by the computer.

Print Quality

This takes into consideration the neatness and the visibility of data printed on paper.

Output Devices

These are peripheral devices which receives information in the form of electrical impulses and so produce an output available to the user whether on a soft medium or on a hard medium. Output Devices enables people to see, hear and even feel the results of processing operations. An Output Device is a peripheral that can make output accessible to people. The most widely used Output Devices are Printers and Visual Display Units (VDU) – Monitors.

Examples of Output Devices

Video Adapters

The image displayed on a monitor is generated by a Video Adapter (also called Display Adapter/Video Card/Graphics Card), an expansion board that plugs into one of the computer’s expansion slots on the Motherboard. The Video Adapter determines the overall quality of the image that the monitor displays. Video Adapters contain their own processing circuitry as well as their own memory (Video RAM – VRAM). Because Video Adapters have their own memory and processors, they free the computer’s chief memory (RAM) and the CPU for other tasks.

Visual Display Unit (V.D.U) (Monitor)

Also called a Display is a television-like device used to produce soft copy output of processed data in a visual form. This device displays the Video Adapter’s output. The on-screen display enables the user to see how programs are processing and presenting information. It is used to display Soft Copy/Temporary Output of information. Types of Monitors/Displays/VDUs include: Cathode Ray Tube (CRT), Liquid Crystal Display (LCD), etc. Dot Pitch is a term that is used to determine the quality of a monitor. This term refers to the width of each physical dot on the screen. A pitch of .28mm or lower is considered good.

Data Projectors

This device takes a computer’s video output and project this output onto a screen, so that an audience can see it.

Plotter

This is a device that produces high-precision graphic hard copy output of information and drawings on paper.

Voice Response Unit/Voice Output Devices

A device that enables output from a computer system in the form of user recorded words/phrases, music, alarms or anything that can be recorded as sounds.

Printer

This is a device used to produce output on a hard medium such as paper. They are used to produce permanent version of output that’s visible on the computer’s display screen

CATEGORIES OF PRINTERS

IMPACT PRINTERS

These printers creates an impact of characters on paper by using a hammer-like device which hits the ribbon in the printer and creates the characters by the impact impression gained from the hammer striking against the ribbon on paper.

NON-IMPACT PRINTERS

A Non-Impact Printer uses a method other than creating impact on paper by using a hammer to hit against a ribbon. One of the methods used by Non-Impact Printers is lazer technology where data is burnt onto special paper (heat sensitive). Another method used is where ink is sprayed on paper to form characters.

TYPES OF PRINTERS

Character Printer

A Character Printer prints one character at a time. This printer produces high quality output of information because this printer prints slower when compared with other types of printers. This printer is an example of an Impact Printer.

Daisy Wheel Printer

The Daisy Wheel Printer produces letter quality output normally used with a word processor application program (e.g. Word Perfect or Microsoft Word). An inter-changing Daisy Wheel that resembles the flower petal it got its name from seeing to its appearance, contains a set of fully formed characters, which spins to the desired character when printing. A hammer strikes the character embedded on the print wheel that is hit against a ribbon to form the corresponding character/image on paper. This printer is an example of an Impact Printer. This type of printing is normally used with electronic typewriters.

Dot Matrix Printer

The Dot Matrix Printer arranges printed dots closely to each other to form characters on paper. This printer is an example of an Impact Printer.

Line Printer

A Line Printer prints one line of characters/information at a time. The Line Printer is normally a type of Dot Matrix Printer. This printer is an example of an Impact Printer.

Page Printer

As its name suggests, it prints a page of information at a time. This printer is another example of a Non-Impact Printer and uses a variety of technologies to achieve high quality hard copy output of information on paper. This printer more times uses lazer technology to print or when printing information. This type of printer is an example of a Non-Impact Printers.

Ink-Jet Printer

This is a type of printer that spits dots of ink on paper to form images in much the same way as Dot Matrix Printer prints. The quality of output is yet higher when compared to the quality given by the Dot Matrix Printer. This printer is an example of a Non-Impact Printer.

Thermal Printer

This printer uses heat elements (lazer technology) to burn (create) characters on special paper, which is heat sensitive. The major disadvantage of this printer is the cost of the heat sensitive paper. The advantage though is the compact size, which it is, less noise is produced when printing and therefore is ideal to be used in business offices. This printer is an example of Non-Impact Printer.

TERMS ASSOCIATED WITH OUTPUT

Resolution

This is the number of addressable points (Pixels) on a monitor used to make up an image. The greater the number of points, the higher the resolution. Resolution generally refers to the sharpness of images displayed by a Monitor. Monitor manufacturers normally state the screen resolution by specifying the number of horizontal picture elements that the screen can display followed by an “x” Common PC resolution are: 640 x 480, 800 x 600, 1024 x 1200, etc.

Pixels

Short for picture element, the smallest element that a device can display and out of which the displayed image is constructed.

Additional Content:

· Liquid Crystal Display (LCD) vs. Cathode Ray Tube (CRT) Monitors

· LCD Projectors

· Infocus Cameras

· Multifunction Printers

· Tactile Output Devices

	Erstellt von Craig Thompson vor etwa 8 Jahre

Output devices there usage and function