The discovery of a crucial concept behind the invention of television was an accident! In 1872, Joseph May, an English telegraph worker, kept a piece of selenium wire near a window. Soon, May found that when sunlight fell on it, its electrical conductivity (measurement of its ability to conduct electric current) kept changing. This showed that light could be converted into electrical signals!
Maurice LeBlanc, a French engineer, published an article in 1880 that later also became the core of television technology. He put forth the idea of a device that would mimic our retina’s ability to “store” an image for a certain duration of time. This device would scan an image in a line-by-line fashion from top to bottom, send the information to a receiver, and the receiver would then recreate the image.
In 1925, the first human face was seen on television. This was done by John Logie Baird, a Scottish inventor.
In 1932, there was a legal battle between the Radio Corporation of America (RCA) and a man named Philo Farnsworth, where both claimed themselves to be the inventor of electronic television. Farnsworth won. He had demonstrated the working of a basic electronic system in San Franciso, back in 1927.
In India, television became prominent due to Doordarshan’s programmes. Doordarshan is a broadcaster and channel started by the government of India in 1959.
The small satellite dishes placed on rooftops of houses and buildings pick up signals from much larger satellites that orbit the Earth. These satellites are in geosynchronous orbit. This means that they revolve around the Earth at the same speed as that of Earth’s rotation. This is how satellite television broadcasting works!
Television sets first became flat with the invention of plasma TV. Fluorescent lights were used to display images in this display technology. These TVs came out in 1997.
From then to now, televisions have changed a lot! To find out more about the evolution of TVs, read Tinkle 794 W2!