Output devices

Plotters. A plotter is an output device that produces line drawings. These devices move a piece of paper under a series of moving pens. As the paper moves, the pens draw. Many plotters produce colour output by drawing with several different-coloured pens. Because it uses fine-point pens, the lines produced with a plotter can be very precise. Plotters are most often used to produce architectural drawings, maps, charts, and other technical types of line art.

Other Output Devices. While the most customary output devices are monitors and printers, not all such devices produce readable information. Computer-generated music and the movement of a robotic arm are just two items in a long list of different types of output from a variety of devices.

Portable Monitors. Portable, laptop, and notebook computers are microcomputers that have become smaller and smaller in size and weight. One of the devices that has made their development possible is the flat-panel monitor. These compact devices consume little power, and their flat profile allows them to provide a full screen in a small folding unit. Early flat-panel displays were monochrome, but new technologies allow these screens to display colour. They can be LCD (liquid crystal display), EL (electrolumines-cent), or gas-plasma:

- LCDs do not consume light of their own, but consist instead of crystal molecules. The backlit LCDs are easier to read than the original LCDs, which were difficult to read in strong light.

- EL screens are an improvement over LCDs because they actively emit light when electrically charged.

- Gas-plasma Screens use a gas that emits light in the presence of an electric current. Unfortunately, gas-plasma displays cannot be battery-operated and must be plugged into a regular AC outlet. This limits their use in portable computers.

Date: 2015-01-02; view: 1087