Output

This is supposed to be the 5th week of my Computer class but since our lecturer canceled the classes throughout last week, hence we still at the 3rd week's schedule.

Another bad news is the fact that she's still sick, we got ourselves a temporary instructor. Why is it bad news? Not only that she's only been assigned our class yesterday, she also just found out the main portal where we got our notes from.

So today, we learned about the output devices.

What are the output devices? They are peripherals used to communicate the results of data processing carried out by an information processing system i.e. computer to the outside world. Basically, output devices transform processed digital information into forms that make sense to human.

An example of an output device is monitor. A monitor is a peripheral device that displays computer output on a screen which is referred to as soft copy. It comprises the display device, circuitry and an enclosure. We have two types of monitors: Cathode-Ray Tube (CRT) and Liquid Crystal Display (LCD or flat-panel).

Cathode-Ray Tube resembles televisions. It uses picture tube technology. It's less expensive than an LCD monitor and takes up more desk space and use more energy than LCD monitors.

Next was the Liquid Crystal Display or more likely to be called as LCD for short. In LCDs, the cells sandwiched between 2 transparent layers form images. LCDs are being used for notebook computers, PDAs, cellular phones and PCs. It is more expensive than CRT monitors. Types of LCD monitors are passive-matrix LCD, active-matrix LCD, gas plasma display, and field emission display. Also about LED, another type of LCD that need 40% less energy, mercury-free and one third thinner than the LCD itself.

We proceeded by discussing the terms like screen size, resolution and refresh rate of computer display.

Next was about another output device which is the printer. What is a printer? It is a peripheral device that produces a physical copy or hard copy i.e. printouts of the computer's output. The types of computers we discussed are the inkjet printer a.k.a the bubble-jet, laser printer, thermal printer, dot-matrix printer and last but not least, the plotter.

Inkjet printer makes characters by inserting dots of inks onto paper. The printouts are more like letter-quality and while the cost of the printer is inexpensive, the cost of the ink is quite costly.

Laser printer works more like a copier. The quality is determined by dots per inch (dpi) produced and colour printers are available. By using this type of printer usually you'll need expensive initial costs but actually it's cheaper to operate per page.

Thermal printer uses heat elements to produce images on heat-sensitive paper.

Dot-matrix printer form characters and images using series of small pins on a print head. It's a noisy and produced low quality printouts but low cost is needed.

Plotter is a printer that uses an ink-pen that moves over a large revolving sheet of paper like A3, A2, A1, even A0 papers. Basically, it is used in engineering, drafting, map-making, and seismology.

I'll post the lab practice on Open Source Software, Linux on the entry.