History of Computers - CRT

Introduction

The CRT or Cathode Ray Tube was the primary apparatus in video screens in televisions and monitors up until the relatively modern advent of newer more compact technologies such as LCD and plasma.

Overview

While scientists had been experimenting tentatively with cathode rays for a few decades, the first cathode ray tube that actually became a forerunner to the late 20th century cathode ray tube was the Braun tube. Invented by Karl Braun in 1897, the Braun tube used a focused beam of electrons to light up a fluorescent screen when the two contacted, emitting a visible dot of light were ever the beam was aimed. The beam of electrons, due to the negative charge of the particles, are controlled using a magnetic field which can either attract or repel the beam, depending on the negative or positive charge of the magnet.. Braun also expanded the basic Cathode Ray Tube into a Cathode Ray Oscilloscope, which takes electrical signals and displays those signals upon the fluorescent screen. This oscilloscope provides the basis for the Cathode Ray Tubes of the relative future. This technology was not perfect though and the first Cathode Ray Tube to display a signal well was invented by Vladimir K. Zworykin and was used in a primitive TV screen. The technology behind the CRT continue to increase, the future versions of the CRT able to project millions of colors of pixels.

Significance

The CRT is one of the most important inventions in computing. It was the first feasible way to display an image from a computer. Early computers' displays were a series of flashing lights. If the CRT was not developed computer displays would have never reached the same level as they have now. Also the GUI (see History of Computers - GUI) would never have created and the accessibility of computers would have not increased to levels that make it such an integral part of life. Thus, thanks to the impacts it made the CRT is an important part of computer history.