Tvs :Then & Now

Tvs have been around since the early 20th century and are a very common thing nowadays. Throughout my lifetime I have seen many iterations of tv. Such as:

  • CRT
  • Plasma
  • LCD
  • OLED

But what do these mean and why did they stop being produced? We will look into the history and pros and cons of each set and see what went right and what went wrong.

CRT

This abbreviation stands for cathode ray tube and you may remember these as the tvs that were twice as long as the screen was wide. Contained in a vacuum electrons are shot out of an electron gun and displayed on a fluorescent screen. These tvs have a maximum refresh rate of 120Hz. However they used composite cables, as to today’s hdmi or displayport, which is a major downside when it comes to any kind of digital conversion such as blu ray.

Image result for crt tv

(crt)

Plasma

Plasma is a different set up to CRT as it no longer uses an electron gun but instead uses ionized gas that responds to electric fields. The main problem with this design was the burn in on the display caused by phosphors in the screen. This mainly came about with the use of letterbox (black bars top and bottom) or 4:3 (black bars on the left and right), which came about due to the change from 576i display to 1080i and the way the broadcaster chose to upscale it. If you watch an old episode of the simpsons on sky you will see these black bars that I’m referencing.

Image result for plasma tv

(Plasma)

LCD

Liquid crystal displays work in a cool and different way. They use the light modulating properties of liquid crystal. This means that a back light is present which allows the colours to be formed. However this can lead to a problem with the depth of some colours and the deepness of the colour black. While the screen may be black it is still back lit to produce the other colours and this leads to the blacks looking nowhere near as crisp as before, where a comparison was made to old crts where the colours were more deep

Image result for lcdtv

(LCD)

Oled

This isn’t just a standard L.E.D but rather an organic light emitting diode. This means every pixel group is lit individually which leads to very deep blacks and colour but also a very deep hole in your wallet as they are a very expensive new technology. The technology behind it isn’t flawless… just like its predecessor it is prone to screen burn in as well as blues fading faster than its red and green counterparts.

Image result for oled tv

(OLED)

HDR

Not all tvs are made equal this means that they don’t all have the same properties, most tvs now use high dynamic range to increase their colour. This is great for movies and games because it allows for a more colour correct image that the human eye would form than a digital interpretation.

Image result for hdr with and without comparison

(HDR left, No HDR right)

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