Perfect Computer Notes

Printers A printer is an output device that prints characters, symbols and graphics on paper. The printed output is called hard copy. Printers produce permanent documents. Print resolution is commonly measured in dots per inch (dpi). A printer with higher print resolution, that is, dpi will produce higher quality print outs, but it will cost higher too. Types of Printers Depending upon the mechanism of printing, there different types of printers, as follows: 1) Impact Printers 2) Non-Impact Printers 1. Impact Printers An impact printer works like a typewriter. It prints characters or images by striking a print hammer , a typeface or pins against paper and inked ribbon. We can say that impact printers do hit or impact an inked ribbon to print on a paper. Since, impact printers produce print outs by striking mechanism, they make a lot of noise, too. Print quality of impact printers is lower than print quality of non-impact printers. Printing cost or impact printers is l

Difference between CRT monitors and Flat Panel (LCD) Monitors Differences between CRT Monitors and Flat-panel (LCD) Monitors CRT Monitors Flat-panel (LCD)Monitors 1 CRT monitors are low-priced and more economical than flat-panel (LCD) monitors. Flat-panel monitors are more costly than CRT monitors. 2 Commonly, CRT monitors are used with personal computers. In the beginning LCD monitors were used in lap top or note book computers, PDAs and smart phones. But now they available for PCs, too.  3 CRT monitors use Cathode Ray Tube (picture tube) Technology to show text and graphics on screen. Flat-panel monitors use LCD - Liquid Crystal Display technology or Gas Plasma technology. 4 CRT monitors need more power. LCD monitors uses less energy than CRT monitors. 5 CRT monitors take more space on desk. LCD monitors take less space on desk top. 6 I

Monitor Monitor is the most familiar output device. It is a display screen or visual display unit to show text and graphics to computer user. Common monitors look like a TV. Latest monitors are flat panel monitors like LCD monitors. Although LCD monitors are more costly than general old fashioned monitors called CRT monitors, they are light weight and don't emit radiations harmful to eyes. Types of Monitors There are the following main types of Monitors: 1. CRT Monitors 2. Flat Panel Monitors 3. Touch Screen Monitors 1. CRT Monitors CRT stands for Cathode Ray Tube. CRT monitors use electronic beam gun to produce text and images. These electronic guns fire a beam of electrons on very tiny phosphorus dots on internal surface of screen. In color CRT monitors there are three electron beam guns for Red, Green and Blue colors. CRT monitors take more space on desk. These are heavier than flat panel monitors. CRT monitors emit radiations which are harmful for human eyes