Changes

A curious application of the CRT was as a form of computer memory, the ''Williams tube.'' In this application, the CRT "writes" by depositing a pattern of charge on the screen, and "reads" by scanning the screen and detecting small differences in current caused by the pattern of charge deposited during the write cycle. Williams tubes were temperamental and unreliable, but enjoyed a brief vogue circa 1950.

A curious application of the CRT was as a form of computer memory, the ''Williams tube.'' In this application, the CRT "writes" by depositing a pattern of charge on the screen, and "reads" by scanning the screen and detecting small differences in current caused by the pattern of charge deposited during the write cycle. Williams tubes were temperamental and unreliable, but enjoyed a brief vogue circa 1950.

Driven by the huge volume of consumer applications, cathode-ray tubes advanced enormously in the second half of the century. Very large tubes were developed in order to meet the need for large television screens. The glass envelopes, originally circular in shape, became rectangular to save space. Various forms of color CRTs were developed, the commonest employed three separate electron beams, three different colors of phosphor dots, and a "shadow mask" insure that each beam struck only the dots of its corresponding color. As computers became common in the last quarter of a century, color CRTs became sharper and higher in resolution, and the screen itself—original shaped like a section of a sphere centered on the electron gun—became shallower and, eventually, completely flat, to minimize reflections.

Driven by the huge volume of consumer applications, cathode-ray tubes advanced enormously in the second half of the century. Very large tubes were developed in order to meet the need for large television screens. The glass envelopes, originally circular in shape, became rectangular to save space. Various forms of color CRTs were developed, the commonest employed three separate electron beams, three different colors of phosphor dots, and a "shadow mask" ensure that each beam struck only the dots of its corresponding color. As computers became common in the last quarter of a century, color CRTs became sharper and higher in resolution, and the screen itself—original shaped like a section of a sphere centered on the electron gun—became shallower and, eventually, completely flat, to minimize reflections.

Around the year 2000, solid state flat-panel displays began to drop in price to the point of becoming competitive with CRTs, and as of 2007 the era of the CRT appears to be drawing to a close.

Around the year 2000, solid state flat-panel displays began to drop in price to the point of becoming competitive with CRTs, and as of 2007 the era of the CRT appears to be drawing to a close.