Browse Definitions:
Definition

cathode ray tube (CRT)

A cathode ray tube (CRT) is a specialized vacuumtube in which images are produced when an electron beam strikes aphosphorescent surface. Most desktop computer displays make useof CRTs. The CRT in a computer display is similar to the"picture tube" in a television receiver.

A cathode ray tube consists of several basiccomponents, as illustrated below. The electron gun generates anarrow beam of electrons. The anodes accelerate the electrons.Deflecting coils produce an extremely low frequency electromagnetic field that allowsfor constant adjustment of the direction of the electron beam.There are two sets of deflecting coils: horizontal and vertical.(In the illustration, only one set of coils is shown forsimplicity.) The intensity of the beam can be varied. Theelectron beam produces a tiny, bright visible spot when itstrikes the phosphor-coated screen.

To produce an image on the screen, complexsignals are applied to the deflecting coils, and also to theapparatus that controls the intensity of the electron beam. Thiscauses the spot to race across the screen from right to left, andfrom top to bottom, in a sequence of horizontal lines called theraster. As viewed from the front of the CRT, the spot moves in apattern similar to the way your eyes move when you read asingle-column page of text. But the scanning takes place at sucha rapid rate that your eye sees a constant image over the entirescreen.

The illustration shows only one electron gun.This is typical of a monochrome, or single-color, CRT. However,virtually all CRTs today render color images. These devices havethree electron guns, one for the primary color red, one for theprimary color green, and one for the primary color blue. The CRTthus produces three overlapping images: one in red (R), one ingreen (G), and one in blue (B). This is the so-called RGB colormodel.

In computer systems, there are several display modes, or setsof specifications according to which the CRT operates. The mostcommon specification for CRT displays is known as SVGA (SuperVideo Graphics Array). Notebook computers typically use liquid crystal display.The technology for these displays is much different than that forCRTs.

This was last updated in September 2005

Join the conversation

9 comments

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

nice post for me.
http://hamaripower.com/crt-monitor
Cancel
im slow learner student short notes on CRT
Cancel
i love u
Cancel
Damnit..
Cancel
reply me quickly
Cancel
Thanks
Cancel
What is a space bar?
Cancel
ni pellam p****
Cancel
"Most desktop computer displays make useof CRTs"
Last century called. They want their CRT back.
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces.

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...

SearchSecurity

  • FIDO (Fast Identity Online)

    FIDO (Fast ID Online) is a set of technology-agnostic security specifications for strong authentication. FIDO is developed by the...

  • cryptanalysis

    Cryptanalysis is the study of ciphertext, ciphers and cryptosystems with the aim of understanding how they work and finding and ...

  • Trojan horse (computing)

    In computing, a Trojan horse is a program that appears harmless, but is, in fact, malicious.

SearchHealthIT

SearchDisasterRecovery

  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

SearchStorage

  • cloud storage provider

    A cloud storage provider, also known as a managed service provider (MSP), is a company that offers organizations and individuals ...

  • personal cloud storage (PCS)

    Personal cloud storage (PCS) enables users to store data, photos, music, videos and other files on a local network-attached ...

  • cloud SLA (cloud service-level agreement)

    A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a ...

SearchSolidStateStorage

  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.

Close