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Technology ---> TV ---> CRT (Cathode Ray Tube)


The CRT, or Cathode Ray Tube (or tube TV) is the oldest form of television. For about 70 years, the CRT dominated the display market, until it was dethroned by today's LCD, Plasma, and DLP displays.


How it works:

On a CRT, a heated filament (the cathode) is placed inside a vacuum, which is created in a glass tube. The inside of the screen, which is coated with red, green, and blue phosphors, is scanned repeatedly in a rectangular pattern called a raster. Three electron beams (the "ray"), one for each primary color (red, green, and blue), are accelerated from the cathode by an anode, and strike the phosphor-coated screen, causing them to glow. Electron coils are used to control where the electron beams are placed on the screen. This process creates the beautiful picture that we see on the other side of the screen.




Sony 32" Trinitron CRT Model KD32FS170




CRTs have been in use for over 80 years, which means that all of the kinks and other issues have been worked out. Also, CRTs have many less electronic components compared to today's LCD, Plasma, and OLED displays, so chances of failure are greatly reduced. Unlike an LCD, there are no pixels to fail, and no bulbs to change either, like on many older rear projection televisions. It's not uncommon for a CRT to last 20+ years, but the other current technologies tend to fail or dissipate in quality over time. Although CRTs are quite difficult to come by these days, if you have one in your home, chances are its still working.


Great Picture quality

Despite being much older technology, CRTs still display a beautiful picture, even compared to today's televisions. Some of the last-produced CRT televisions were high definition, capable of displaying 720P/1080i, and the picture was absolutely stunning. Just check out Samsung's old SlimFit lineup.


Samsung 30" Slimfit CRT Model TXT3092WH

Great viewing angle

Compared to a rear projection TV, CRTs have a great viewing angle, since the light is created by the phosphor- coated on the screen.  



Due its odd shape, the cabinet for a large-size CRT usually left a lot of extra space inside. What better way to fill this void by adding better speakers? What the CRTs lacked in screen quality, the manufactures could compensate for by added better sound quality. Unlike some flat-screens where a home theater system is almost necessary for great sound, the upper-end CRTs like Sony's Trinitron line-up came standard with all the sound you needed. 




Today, many viewers have decided to go with larger screens. For CRTs, this is the big limiting factor. As you increase screen size, the a television gets longer and wider. In the case of a CRT, the tube also grows along with the size, meaning the television also becomes deeper. This larger CRT increases the TV to exponentially increase in weight. Weight restrictions limited CRTs to 43" in size, and most manufacturers stopped at 36". This increased weight also made TVs quite difficult to move around. Transporting a 36" CRT by hand requires the strength of at least 3 average-sized people.



One of the main disadvantages of CRT televisions over LCDs is their tendency to receive burn-in. If a CRT is left on a frozen image (paused movie, network logo, weather report, etc.) for a long period, that frozen image may get burned into the screen. This is due to the constant intensity placed on that portion of the screen. However, this does take a while to occur. It's more common to see burn-in on CRT computer monitors or old arcade machines. Also, if noticed early, burn-in can usually be cleared up by placing the television on a white screen.



Compared to today's LCDs, the CRT is somewhat dim. CRTs do not have a backlighting system, and rely solely on the phosphors to create light.


With its bulky shape, the CRT may seem a bit primitive compared to its successors, but it is more than capable of displaying a beautiful picture, and still remains the most reliable display technology to date. In fact, don't be surprised if CRTs make a return in the near future, in a different form.