CRT monitor

Cathode Ray Tube (CRT) Overview

CRT refers to cathode ray tube. Now days CRT displays are primarily designed to use in rugged and harsh industrial environments such as factory floors and control rooms. A cathode ray tube (CRT) is a sealed vacuum glass tube. It contains a neck and a large base as a monitor or display screen. A matrix of tiny phosphor dots covers the inside of the screen.

Cathode Ray Tube (CRT) Display Specifications

Displays of a CRT monitor are specified their color, image resolution, diagonal, and vertical scanning frequency.

Cathode Ray Tube (CRT) Colors

CRT monitors are available in both color and monochrome displays. Different techniques are used to generate colors on a cathode ray tube (CRT). One technique is varying the combinations of various discrete colors to generate a range of colors. The most common technique is RGB sensing. The screen sense re, green, and blue (RGB) colors and combines them to generate a wide range of colors. Monochrome displays show only black, white, or gray colors.

Cathode Ray Tube (CRT) scanning frequency

Vertical canning frequency is the refresh rate of the CRT display or screen. It defines how quickly the image is refreshed. In other words it is the rate at which a pixel is re drawn. Displays with lower refresh rate cause flickering. Minimum of 85 Hz of refresh rate displays flicker-free image.

Cathode Ray Tube (CRT) Resolution

Resolution refers to the sharpness of the image on CRT screen. Higher resolution means sharper images. Diagonal measurement also affects the resolution. CRT displays with larger diagonals relatively require higher resolutions. Diagonal choices for CRT displays include 10, 12, 14, 15,17, 19, 21, 23, and 25 inches.

Cathode Ray Tube (CRT) Technology

Three types of technologies are used in CRT monitors. These include shadow mask, aperture grille, and enhanced dot pitch.

CRT Shadow Mask Displays

A shadow mask refers to the metal sheet. This metal sheet contains holes, which are placed in front of coated phosphor dots of the tube. The electron beam is passed through these holes. This narrows the beam and puts at the phosphor dots more accurately.

CRT Aperture Grill Displays

An aperture grille consists of fine metal strips. The strips are strung at a very high tension from top to bottom inside the tube. No phosphor line break up, strip tension, and other grill design attributes allow greater amount of electron beam to the target. This provides brighter picture, vertically flat display, and reduced glare and image distortion.

CRT EDP Displays

CRT enhanced dot pitch (EDP) displays differ from others due to phosphor implementation. In EDP technology the phosphor dots are placed relatively close. The dots are prolonged to get oval shape rather than round. Reduced distance and elongated shape make the target phosphor more visible to electron beam.

CRT physical Specifications

Physically CRT monitors can be specified by user controls, mounting styles, and external connections. User controls refer to the controls at front, rear, and on screen control options. In mounting options CRT monitors are available in rack mount, panel mount, and chassis mount. External connections vary among various CRT monitors. These may include serial interfaces, parallel interfaces, SCSI, USB, or mouse and keyboard ports.