Computer Peripherals - Mr Mark's ICT Website

Computer Peripherals

Keyboard
A very common, general purpose, input device with text(abc…), numbers (123…) and symbols (%$@...) to be entered into a computer.

A keyboard is simply a set of buttons. Each button has a symbol assigned.
The type

Connectivity Options: Wired and Wireless
Layout and Ergonomics
Keys and Switches
Mechanical Keyboards
Customization

Flexible Keyboard

These keyboards work just the same as standard keyboards but are meant for people on the move.

They are typically made of silicon, which is water and dust-resistant and don’t require constant cleaning.

No additional keyboard cover skin required, food crumbs or dust can be easily cleaned thoroughly.

Clean the silicone keyboard with water, alcohol, or alcohol based disinfectant.

Ergonomic Keyboard

.The ergonomic keyboard is designed to reduce the strain of constant typing on the wrist and other problems that stem from that.

Ergonomic keyboards are designed to angle the hands the way they would naturally fall and typically feature padding for the wrists to rest on.

The help is reducing RSI (Repetitive Strain Injury)

Gaming Keyboard

Gaming keyboards are created for use for long periods of time, often adopting ergonomic designs for comfort and also lighted keys for playing in the night.

These keyboards are also built with programmable keys that can be adapted to the kind of gamer you are.

They have an extra thick coat of paint on the keys, more often used for gaming, such a W, A, S, D and the space bar.

Three zone dynamic RGB backlighting with 10+ preconfigured vivid RGB lighting modes allow you to choose immersive lighting effects

Wireless Keyboard

The wireless keyboard is exactly what it’s called; a keyboard without a wire. It is connected to your computer with infrared, 2.4 GHz WiFi or more often through Bluetooth.

These keyboards can be used if you connect your computer to either a screen or television so you can control it from the comfort of your bed or sofa.

They are relatively inexpensive and very easily available.

Rechargeable lithium battery with an industry-high capacity lasts for 6 months with single charge

Projection Keyboard

Finally, probably the coolest keyboard of the lot is the projection keyboard.

This is a device that can be connected through Bluetooth to your mini PC, tablet computer or even smartphone. It shows the laser projection of a keyboard on any plain surface that you choose.

You type on the holograph of the keys and the device records your key strokes and responds accordingly. Welcome to the future!

Mouse

This is an Input device. The mouse, sometimes called a pointer, is a hand-operated input device used to manipulate objects on a computer screen. There are different types of Mice. These are:
Wireless mouse
Trackball mouse
Optical mouse
Laser mouse
Ball mouse
Optical- Mechanical mouse

WIRELESS MOUSE

Otherwise known as a cordless mouse, these refer to every mouse that does not have a piece of cable sticking out.

There are 2 parts to the equation:

The mouse itself acts as the transmitter, giving out wireless signals as you move and click.

The computer will receive those wireless signals and act accordingly

As to the “wireless signals” part, please take note that it is not universal – Some wireless mouse uses the common Bluetooth standard, some uses a 2.4 GHz wireless standard, and a few others have their own proprietary wireless USB dongle.

WIRED MOUSE

As you might have guessed it, wired mice refer to every mouse that has an attached cable and requires to be plugged into a computer device.

For those who are thinking that wired mice are “low tech”, “outdated”, and “inferior” – They are not, and are essentially the same as their wireless counterparts…

Less the wireless circuits, and no batteries required.

MECHANICAL MOUSE

The mechanical mouse is what we use in the good old days and one of the most traditional mice in the history of computers.

It is otherwise known as a ball mouse because it uses a rubber ball to detect motion.

That ball spins along as you move the mouse, and sensors will pick up on which direction you moved.

OPTICAL MOUSE

This is the common Joe mouse that you see everywhere these days.

But instead of using a rubber ball and mechanical sensors, an optical mouse uses an LED and detects movement by sensing changes in the reflected light.

GAMING MOUSE

While a typical mouse usually only have 3 buttons, a gaming mouse is characterized by having many buttons and touting itself to be accurate.

These extra buttons are often programmable to do various things.

Mostly for the purpose of gaming.

Monitor

The monitor is the piece of computer hardware that displays the video and graphics information generated by the computer through the video card. Monitors are very similar to televisions but usually display information at a much higher resolution. A monitor, no matter the type, usually connects to either an HDMI, DVI, or VGA port. Other connectors include USB, DisplayPort, and Thunderbolt.

TFT and LCD are two of the technologies used in flat-screen monitors:

TFT is Thin-Film-Transistor.
LCD is Liquid-Crystal Display.

Another technology that may replace these is OLED, or Organic Light-Emitting Diodes.

TFT Monitor

Short for thin film transistor, a type of LCD flat-panel display screen, in which each pixel is controlled by from one to four transistors.

The TFT technology provides the best resolution of all the flat-panel techniques, but it is also the most expensive. TFT screens are sometimes called active-matrix LCDs.

LCD Monitor

IStands for "Liquid Crystal Display." LCD is a flat panel display technology commonly used in TVs and computer monitors.

It is also used in screens for mobile devices, such as laptops, tablets, and smartphones. LCD displays don't just look different than bulky CRT monitors, the way they operate is significantly different as well.

Instead of firing electrons at a glass screen, an LCD has back light that provides light to individual pixels arranged in a rectangular grid.

Each pixel has a red, green, and blue RGB sub-pixel that can be turned on or off.

When all of a pixel's sub-pixels are turned off, it appears black. When all the sub-pixels are turned on 100%, it appears white.

By adjusting the individual levels of red, green, and blue light, millions of color combinations are possible.

Speakers
Speakers are one of the most common output devices used with computer systems. Some speakers are designed to work specifically with computers, while others can be hooked up to any type of sound system. Regardless of their design, the purpose of speakers is to produce audio output that can be heard by the listener.
All speakers have different quality. You should consider the following when buying speakers:

Sensitivity: Measured in dB (decibels), it is one of the most significant albeit ignored, speaker specifications. A speaker's sensitivity indicates the loudness of a speaker

Frequency Response: It is sometimes mentioned as frequency range and is measured in Hertz (Hz). This specification in a speaker tells how low and high a speaker can play.

Power Handling: Specified in Watts (W), the power handling specification of a speaker indicates how much power a speaker can bear without causing any damage.

Microphone
A microphone is a device that captures audio by converting sound waves into an electrical signal. This signal can be amplified as an analog signal or may be converted to a digital signal, which can be processed by a computer.

Webcam
A webcam is a video camera that feeds or streams its image in real time to or through a computer to a computer network. When "captured" by the computer, the video stream may be saved, viewed or sent on to other networks travelling through systems such as the internet, and e-mailed as an attachment.

720p and 1080p are high-definition resolutions, with 1080p being the best available. The "P" is short for "progressive scanning."
For example, 720p really means 1280x720 pixels, where 1280 represents the number of horizontal pixels and 720 represents the number of vertical pixels. A 720p television will progressively scan 921,600 pixels (1280x720) on the screen every 1/60 of a second. The more pixels that can be progressively scanned onscreen, the better the video quality.

USB Flash Drive

This is both an Input and Output device.
The definition of a USB flash drive is a small, portable data-storage device that plugs into the USB port on the computer and uses solid-state flash memory to store data.

Size - Can be many sizes but mostly measureed in Gb ( 2Gb, 4Gb, 8Gb, 16Gb, 32GB)

Speed - Megabits per second (Mbps or Gigabytes per second Gbps). The lager the number the faster it can read and write.
If we compare USB 2.0 and 3.0 there are some major differences. First the transfer rates: USB 2.0 offers transfer rates of 480 Mbps and USB 3.0 offers transfer rates of 4.8 Gbps; that's 10 time faster.

Printer
A printer is an output device that prints paper documents. This includes text documents, images, or a combination of both.

Dot Matrix Printer

A dot-matrix printer is named after the pattern (a grid or ‘matrix’) of dots used when creating the paper printout.

These dots are formed by tiny pins in the printer’s print head that hit an inked ribbon against the paper leaving marks.

As the print head moves along it leaves a pattern of dots behind it which can form letters, images.

Dot-matrix print quality is poor, the printers are noisy, and there are much better printing systems available today.

However, the dot-matrix printers are still used in certain situations:
Since the pins actually hit the paper, several ‘carbon-copies’ can be printed in one go.

An example of this is airline tickets which have several duplicate pages, all printed in one go

The print mechanism is very cheap, and the inked ribbons last for a long time. So, where cheap, low-quality printouts are required, dot-matrix printers are used. An example is shop receipts.

InkJet Printer

Cheap, high-quality, full-colour printing became available during the 1980s due to the development of ink-jet printers.

These printers have a similar print-head mechanism to a dot-matrix printer. The print-head passes left and right across the paper. However, instead of using pins to hit inky marks onto the paper, the ink-jet squirts tiny droplets of ink onto the surface of the paper. Several coloured inks can be used to produce full-colour printouts.

The droplets of ink come from tiny holes (the jets) which are less than the width of a human hair in size. Each droplet creates a tiny dot on the paper. Since the dots are so small, the quality of the printout is excellent (1200 dots-per-inch are possible). This is perfect for photographs.

Ink-jet printers are very quiet in use. Since they have so few moving parts they are also cheap to manufacture and thus cheap to purchase. However, the ink is very expensive to buy (this is how the printer companies make their profits!) so the printers are expensive to use.

Laser Printer

Laser printers are very complex devices, and thus expensive to buy. However they are very cheap to use. This is because they produce marks on paper using a fine dust called toner which is relatively cheap to buy. A single toner cartridge will often last for 5,000-10,000 pages of printing.

The laser printer uses a complex system, involving a laser, to make the toner stick to the required parts of the paper. (This system is very different to a dot-matrix or ink-jet, and you don’t need to know the details.)

The laser and toner system allows very fast printing compared to other printers (just a few seconds per page).

Laser printers are very common in offices since they print very quickly, are cheap to use and are reasonably quiet.

Plotter

Plotters create hard-copy in a very different way to printers. Instead of building up text and images from tiny dots, plotters draw on the paper using a pen.

The pens are held in an arm which can lift the pen up or down, and which can move across the paper. The arm and pen create a drawing just like a human could, but much more accurately and more quickly.

Different coloured pens can be used to produce coloured line drawings.

Plotters are often used by designers and architects since they work with huge pieces of paper, far bigger than anything a normal printer could work with...