Look at your modern-day TV, and you witness nothing less than a technological miracle.
Scientists began experimenting with the concept of television more than a century ago. But it wouldn’t be until the 1939 World’s Fair that the Radio Corporation of America introduced it to the general audience. Before TV sets were available in stores, more time had passed, and even then, it took some time before most people got one. Less than 10% of Americans had a television in 1950. By 1959, that number had climbed to 85%.
In addition, early TV shows were in black and white because color wasn’t widely used until the middle of the 1960s.
Viewers didn’t have a lot of choice, either. Most localities only offered three or four channels, as opposed to hundreds.
And DVR didn’t exist. Programs had certain days and times when they aired, and if you missed it, you missed it.
As a professor of electrical and computer engineering, I am surprised by the incredible achievements of this technology in only a few decades.
But regardless of whether you have a modern smart TV that practically covers the wall or an old television with a 5-inch screen, your set still serves three main purposes: to receive audio and video data; to use that data to present the viewer with sound and a picture; and to give the viewer a way to change the channel and the volume.
radio waves, antennas, and transmission towers
Early TVs worked with the use of “analog signals” — effectively radio waves holding both the picture and sound of a television program.
In a nutshell, here is how it went: During the broadcast day, the local television station continually aired those radio waves across the air using a massive transmission tower. A cable carried the signal to the television sets inside by intercepting those waves with antennas on the roofs of nearby homes and buildings.
There, the TV decoded the signal and produced a sound-accompanied picture. Although it wasn’t as sharp as modern TVs, what you saw and heard was still nice.
By 2009, digital TV transmissions, which are the current standard, had taken the place of analog TV signals at TV stations. In comparison to prior TVs, HDTV, or high-definition television, boasts incredible picture quality. The TV picture is still encoded in binary, which is a series of 0s and 1s, but digital signals are still sent by radio waves.
frames, bytes, and bits
Different information streams are used in contemporary digital TV. For instance, one stream is used for the image and another is used for the audio.
Basic building blocks called pixels are used to make images. Tens of thousands of pixels make up your TV screen, and each one has a “color index” and a “intensity.” Basically, the three colors red, blue, and green combine to create additional colors in different ways, and the finished image is made up of all the pixels put together. The desired image is produced by adjusting the quantity and intensity of each color pixel, much like mixing paint to create any color you like.
Bytes are larger units made up of groups of bits. They serve as the conduit for information between your TV and the content you are watching. This information is packaged and unpackaged by a modem, which is the fundamental component of every TV and cellphone.
The bundled data can be delivered over the air, by fiber optics, or cable, where they are received by your TV using a cable box. A service that has gained a lot of popularity is streaming TV, which uses data from a computer network.
The choice is then yours as the viewer. An interface on your contemporary digital smart TV enables you to manage every feature. A computer, a sizable monitor, and a receiver are all basically included in a smart TV.
The features of your phone and TV will increasingly converge in the future. For instance, the TV will serve as the screen for your telephone. Expect to see more ultra-high definition television, virtual reality, and augmented reality.