The birth of what we know of today as the computer monitor dates back to 1897 when the German physicist Ferdinand Braun created the Cathode Ray Tube (CRT) .
However, it wasn't until 1907 some 10 years after the invention of the CRT that Vladimir Zworykin , a Russian scientist and inventor made improvements to CRT making it possible for them to be used as televisions. Credit should also be given to Philo Taylor Farnsworth and his contribution to making the commercial CRT or television a reality.
So what is a CRT? Well the CRT or Cathode Ray Tube is a negatively charged electron gun that shoots a stream of electrons to a phosphor coated screen. When the electrons come in contact with the screen it is illuminated or glows. Of course this explanation seeks to simplify the internal workings of a CRT. See below for image of a CRT. Image - CRT Monitor Image - CRT Unmasked
The below video helps to provide a better understanding of the internal workings of a CRT.
Video - How a CRT Works.
Here is an example of what the output of a first generation CRT monitor looked like.
Image - CRT Display (Green Screen)
CRT display technology continued to evolved particularly, after Allen B. Dumontrevolutionized the lifespan of CRTs . Below is a chronology of CRT technology until the transition to Liquid Crystal Display.
Evolution of Display Technologies
1888 - Liquid Crystal Display (LCD) discovered by an Austrian scientist Friedrich Reinitzer
1969 - RCA made the world's first Liquid Crystal Display (LCD). However, it was until the 70's that LCD technology was used in electronic calculators. Then in 1996 3Com used LCD display technology in the Palm Pilot handheld.
1981 - IBM CGA - IBM is credited with introducing the first personal computer which was also known at the time as the "three-piece computer" since the monitor, keyboard and CPU were separate pieces. Soon after enhanced the number of colors that a monitor could display to four with the introduction of the Color Graphic Adapter (CGA). A CGA monitor allowed for 320 x 300 resolution.
1984 - IBM EGA - By 1984 IBM enhanced the CGA further by creating the Enhanced Graphic Adapter (EGA). The EGA allowed a monitor to display 16 colors with a resolution of 640 x 350 pixels.
1987- VGA - Three years after the introduction of the EGA, IBM released the Video Graphic Array (VGA) which is still currently well known and used. This is a noteworthy milestone in display technology since up to this point computer displays were limited to text. VGA display technology spurred the growth of computer graphics and with graphics came games. VGA monitors allowed for 256 different colors to be viewed. With more colors the resolution of the display was also increased to 640 x 480.
1990 - XGA and UXGA - With Enhanced Graphic Array (XGA) display technologies made significant improvements going from 256 colors with VGA to 16.8 millions colors using XGA. XGA's display resolution also improved to 800 x 600. As display technology shifted from CRT to Liquid Crystal Displays (LCD), Ultra Extended Graphics Array (UXGA) was introduced to take advantage of bigger LCD displays. The improvement of XGA technology further pushed display resolution to 1600 x 1200.
1990 - Liquid Crystal Display (LCD) became commercially viable in the 90's. This was due to the falling price of material used to make LCDs.
LCD Technology - Now
LCD technology differs from CRT because there is no cathode ray gun shooting electrons on phosphored coated screen. LCDs are made of several layers. The rear layer is the fluorescent light source, which is know as the backlight. The light from this rear most layer passes through another layer that contains polarizing filters. The light becomes polarized after passing through the polarizing filters. It then passes through another layer which contains thousands of liquid crystal blobs arranged in cells. These cells are arranged as rows across the LCD screen with one or more cells creating a pixel. An electrical field around the edge of the screen creates twists the crystal molecules within the display. Each pixel in a Color LCD display is made up of three liquid crystal cells comprising of a red, green or blue filter.
LCD Technology continued to evolve from passive matrix to active matrix technologies.
Some of the advantages of LCD over CRT include; sharper images, lower power consumption, smaller form factors.
1981 - The Monitor
The birth of what we know of today as the computer monitor dates back to 1897 when the German physicist Ferdinand Braun created the Cathode Ray Tube (CRT) .
However, it wasn't until 1907 some 10 years after the invention of the CRT that Vladimir Zworykin , a Russian scientist and inventor made improvements to CRT making it possible for them to be used as televisions. Credit should also be given to Philo Taylor Farnsworth and his contribution to making the commercial CRT or television a reality.
So what is a CRT? Well the CRT or Cathode Ray Tube is a negatively charged electron gun that shoots a stream of electrons to a phosphor coated screen. When the electrons come in contact with the screen it is illuminated or glows. Of course this explanation seeks to simplify the internal workings of a CRT. See below for image of a CRT.
Image - CRT Monitor Image - CRT Unmasked
The below video helps to provide a better understanding of the internal workings of a CRT.
Video - How a CRT Works.
Here is an example of what the output of a first generation CRT monitor looked like.
CRT display technology continued to evolved particularly, after Allen B. Dumont revolutionized the lifespan of CRTs . Below is a chronology of CRT technology until the transition to Liquid Crystal Display.
Evolution of Display Technologies
1888 - Liquid Crystal Display (LCD) discovered by an Austrian scientist Friedrich Reinitzer
1897 - German physicist Ferdinand Braun created the Cathode Ray Tube (CRT)
1969 - RCA made the world's first Liquid Crystal Display (LCD). However, it was until the 70's that LCD technology was used in electronic calculators. Then in 1996 3Com used LCD display technology in the Palm Pilot handheld.
1981 - IBM CGA - IBM is credited with introducing the first personal computer which was also known at the time as the "three-piece computer" since the monitor, keyboard and CPU were separate pieces. Soon after enhanced the number of colors that a monitor could display to four with the introduction of the Color Graphic Adapter (CGA). A CGA monitor allowed for 320 x 300 resolution.
1984 - IBM EGA - By 1984 IBM enhanced the CGA further by creating the Enhanced Graphic Adapter (EGA). The EGA allowed a monitor to display 16 colors with a resolution of 640 x 350 pixels.
1987- VGA - Three years after the introduction of the EGA, IBM released the Video Graphic Array (VGA) which is still currently well known and used. This is a noteworthy milestone in display technology since up to this point computer displays were limited to text. VGA display technology spurred the growth of computer graphics and with graphics came games. VGA monitors allowed for 256 different colors to be viewed. With more colors the resolution of the display was also increased to 640 x 480.
1990 - XGA and UXGA - With Enhanced Graphic Array (XGA) display technologies made significant improvements going from 256 colors with VGA to 16.8 millions colors using XGA. XGA's display resolution also improved to 800 x 600. As display technology shifted from CRT to Liquid Crystal Displays (LCD), Ultra Extended Graphics Array (UXGA) was introduced to take advantage of bigger LCD displays. The improvement of XGA technology further pushed display resolution to 1600 x 1200.
1990 - Liquid Crystal Display (LCD) became commercially viable in the 90's. This was due to the falling price of material used to make LCDs.
LCD Technology - Now
LCD technology differs from CRT because there is no cathode ray gun shooting electrons on phosphored coated screen. LCDs are made of several layers. The rear layer is the fluorescent light source, which is know as the backlight. The light from this rear most layer passes through another layer that contains polarizing filters. The light becomes polarized after passing through the polarizing filters. It then passes through another layer which contains thousands of liquid crystal blobs arranged in cells. These cells are arranged as rows across the LCD screen with one or more cells creating a pixel. An electrical field around the edge of the screen creates twists the crystal molecules within the display. Each pixel in a Color LCD display is made up of three liquid crystal cells comprising of a red, green or blue filter.
LCD Technology continued to evolve from passive matrix to active matrix technologies.
Some of the advantages of LCD over CRT include; sharper images, lower power consumption, smaller form factors.
Provided is a primer in how LCD Technology Works
Resources
Youtube.com. June. 3, 2009, TV pioneer Zworykin believed in spread of knowledge via television
Youtube.com, July 29, 2009, CRT - How Does It Work
"The CRT History Page." The CRT Tube Site. http://members.chello.nl/~h.dijkstra19/page3.html
"The History of Computer Monitors." eHow.com. http://www.ehow.com/about_5459113_history-computer-monitors.html#ixzz0trERTsj1
"Cathode Ray Tube." Wikipedia. http://en.wikipedia.org/wiki/Cathode_ray_tube
"History of the PC Display." Softpedia. http://gadgets.softpedia.com/news/History-of-the-PC-Display-041-01.html
"Brief History of LCD." Tresna. http://www.tresnainstrument.com/brief_history_of_lcd.html
"How LCDs Work." HowStuffWorks. http://electronics.howstuffworks.com/lcd3.htm
"The Magic of An LCD." SmartComputing.com http://www.smartcomputing.com/editorial/article.asp?article=articles/archive/r0607/10r07/10r07.asp&guid