First TVs
What began as an Electric telescope back in 1883 was to develop into a massive industry that rules most peoples’ lives. At the beginning of the twentieth century, frequency amplification tubes made the transmission of images possible. By the early 1920’s images were successfully being sent over short distances. By 1928, the electronic components needed to made the first working TV were completed and the television was on display at New York’s World Fair in 1939.
Way back then, TVs were made with a series of vacuum tubes. They received then converted video signals into electrons. These were then forced through a demodulator, amplifier and separator. The signals were then fired at a phosphorous sheet of glass, back with aluminum. This electronic component became known as the “Cathode ray tube” or CRT.
Venture with us now inside a cathode ray tube, or CRT. Most TVs today rely on electronic components that display images. It is possible to also make something like a TV screen using thousands of everyday 60-watt light bulbs! However, the CRT is the most usual way of displaying an image on a TV screen.
In the 21st century, new ideas such as flat panel screens have embraced the electronic components of the past and moved into new territories. Plasma screens contain thousands of cells filled with phosphor gas pressed between metal electrodes. Screens also have a liquid crystal display (LCD) and some even projection systems. These exciting new developments have moved the “Electric telescope” into a whole new era. It’s TV Jim, but not as we know it …
