Alfred is a long-time teacher and computer enthusiast who works with and troubleshoots a wide range of computing devices.
Computer hardware components that facilitate dissemination of data and information into usable forms are classified as computer output devices. Output hardware read information like text, graphics, video, sound and other digital outputs and present them by sound, visually and onto physical media.
There are two major categories of output hardware:
As the words suggest, softcopy forms are not physical and can only be experienced visually or through sound. Hardcopy outputs are those that can be felt and touched.
These are available in two forms:
- Display output
- Sound output
Softcopy output devices take advantage of sight and sound and are usually accompanied by physical computing devices. For example, you will need a personal computer to watch a movie output and an iPod to listen to your mp3 file.
Display Output Devices
Display output is probably the most common form of output since it allows an instant display of texts, graphics and video immediately as they are manipulated. Take the touch technology, for example, where input and output are experienced simultaneously.
You tap your smartphone screen to watch a movie or doodle using your finger and the results will be instant.
Popular display technology forms include:
- Computer monitor
- Projection display
- Electronic smartboard
A monitor is an electronic visual display component that outputs information in visual forms like texts, graphics and video. Examples of monitor types include:
- Cathode Ray Tube (CRT): a display unit of conical shape and uses an electron gun to fire display onto the display tube. CRT screens offer better contrast ratios and viewing angles than LCD and LED technologies, but due to higher power consumption and unnecessarily extra space they take, CRTs have been abandoned by manufacturers.
- Liquid Crystal Display (LCD): LCDs are flat panels that use compact fluorescent light bulbs embedded with mercury to facilitate display. LCD offer better display in brighter rooms.
- Light Emitting Diode (LED): LED displays are flat panels that use diodes to emit light for display to take place.
- Plasma: plasma screens are flat panels that use gasses made up of electrons and ions, and the movement of electrical current through the plasma gasses causes the atoms to release energy as light. Plasma screens are usually thicker in size and richer in color depth than LCD and LED, but will display washed out images in brighter rooms. They are commonly used as television sets than computer screens.
- Organic Light-Emitting Diode (OLED): OLED screens are thinner than the rest and use organic material with carbon to convert the electric current into light. OLED screens are capable of separately lighting up each picture element unlike the LCD design. This makes OLED screens much brighter and colorful than LED screens.
- HD, Ultra HD And 4K Monitors: Ultra high definition screens are still mostly targeted for television users. They are LED and LCD models which implement more than usual pixels onto the display. 4K screens have four times or more screen resolution (3,840 x 2,160 pixels) than traditional HD screens. This explains why they are much wider than traditional displays.
Projection display technology uses a projection device to beam visual display forms onto a physical background or augmented reality display.
A projector is a computer output device that connects and beams an enlarged computer display onto a physical surface like a wall or canvas. They are commonly used for presentations and other kinds of meetings and workshops to help make displayed data larger for many attendees to view.
A smartboard is an interactive electronic whiteboard designed to take place or work in tandem with traditional whiteboards and chalkboards in education institutions. It can as well project desktop and other data of the computer it is plugged onto.
Unlike chalkboards and whiteboards which used chalk and specialized markers, smartboards are touch-enabled, making it possible to input and view data and information right on the same surface. Apart from using the finger as an input source, special inkless pens and other pointing devices can be used on it.
Augmented Reality Display
Augmented Reality (AR) or computer-mediated reality, makes use of a display device to fool the eye and mind into seeing a much larger display than it actually is.
One such display is featured in Google Glass which uses LED illuminated display technology to beam larger display.
An audio stream input-output (ASIO) device attaches to the sound card port in order to emit output that can be interpreted and heard by human ears.
There are two popular devices in use today for sound output:
Speakers allow you to listen to music and hear sound effects from the computer.
Speakers are built into the computer i.e. laptops and mobile devices, or standalone devices which connect to the computer by use of cable or wireless signals.
Headphone and Earphone
Headphones are head-mounted and are therefore fitted around the head and ears. Earphones meanwhile are tiny little buds that plug directly inside the ear.
Both headphones and earphones connect to computers via cable or Bluetooth wireless signal.
Computer output devices for hardcopy output disseminate data and information into forms that can be visualized and touched, but most importantly available independent of the output device and computer.
The printer is the most common hardcopy output device.
A printer is a peripheral device that receives and converts text and artwork onto paper or 3D form. Several printer technologies exist in the market today:
- Impact printer
- Non-impact printer
- 3D model printer
- Thermal printer
Impact printers make direct physical contact with the paper it is printing onto. Two types of impact printers have been around us for a while. They are:
- Daisy wheel printers
- Dot matrix printers
Daisy Wheel Printer
This was used way back in the 1970s and a little of 1980s. It used a disc that contained all possible alphanumeric characters, just like a typewriter. Upon request to print, the disc rotated and printed the requested number, symbol or letter.
Dot Matrix Printer
A dot matrix printer uses a row of pins through an ink ribbon onto paper, and the quality of the printout is determined by the number of available pins. Printers with more pins will definitely print copies. Most dot matrix printers have 24 pins. Dot matrix printers are called so because of the printed characters that are formed by a matrix of dots during printing.
However, these printers generate a lot of noise and do not produce high-quality work. Dot matrix printers are commonly used by companies in printing pay slips and receipts, where quality is not a priority. An example of this type of printer is Epson LX300.
In non-impact printers, there is no physical contact between the printing mechanism and paper.
Inkjet printers operate by spraying small drops of ink onto paper. Inkjet printers are the most common type of printers, due to their low cost, fair printing quality and color printing. They also make less noise as compared to impact printers.
Though cheaper to buy, the print per page cost in an inkjet printer is much higher, and the print speed is not as fast as in laser jets.
A laserjet printer produces high-quality printouts than the rest of personal printers. Laser stands for light amplification by simulated emission of radiation.
Laserjets use laser technology and toner to send information onto paper. Toner in a laser printer is a powder material.
A laser beam projects an image onto a rotating drum. The drum then prints the image onto paper by using direct heat and fusing the ink onto paper.
Laserjet printers either ship in monochrome or color. Besides the black toner cartridge in a monochrome printer, the color laserjet printer has three other cartridges with the colors, cyan magenta and yellow.
3D printing also known as desktop fabrication is the process of making three-dimensional solid objects from a 3D model on the computer.
To create 3D models, you will need to draw models using design software or assemble and stitch a set of 3D images. 3D files are saved in .stl file format and then sent to the printer.
The concept of printing a three-dimensional object using a 3D printer is actually similar to basic printing using inkjet printers.
Technically, the printout object is created when layers of liquid print material are deposited on the print surface till the desired 3D solid object is achieved. Unlike the impact and non-impact printing mentioned above, 3D printing works by additive procedures though.
Even so, 3D printing varies from printer to technology with some printouts modeled out of melted materials and others from special paper.
A thermal printer prints by heating regions of heat waxy paper. The image is created on the waxy paper by burning dots on it. For colored output, colored waxy sheets are used.
Thermal printers are commonly used in cash registers and ATMs.
Other Printer Technology
- Solid printer
- Label printer
- Wide format printer
- Dye sublimation printer
- Braille printer
- Photo printer
- Microfilm printer
Cloud printing is another big leap in cloud services. A technology championed by Google, cloud printing permits printing beyond borders.
A Google account can be configured to install and prepare a Google cloud printer or any standard local printer to be used across the internet.
What this means is that you can set up your local printer in London and print your work using another computer when in Kampala or Tokyo, right within your Gmail account.
Cloud printing is even more convenient if you wish to print a document right from your mobile phone. Google cloud printing supports both Android and IOS.
Other Computer Output Devices
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2014 Alfred Amuno
Alfred Amuno (author) from Kampala on June 24, 2014:
Thanks Arthur. I have a few hubs which illustrate the workings of cloud computing. You could start with these two:
Arthur Keyword from Kenya on June 24, 2014:
It seems that you know a lot technology. But, could be possible if you could give me more information about cloud services . I would highly appreciate your effort if you did that for me