Televisions have evolved from black and white to color, from brown tube to flat panel displays, and more recently to smart TVs, offering a wide range of features. In the future, the combination of artificial intelligence and the Internet of Things will bring even more revolutionary changes.
Television (TV), one of the main electronic devices in our homes, is a method of telecommunication in which an optical image of an object is carried on radio waves and reproduced on a receiving device, or a receiving device that receives the image. The word television comes from the Greek tele, meaning “far,” and vision, meaning “to see” in Latin. The principle of the technology is to convert the image sent by a station into radio waves, which are received by an antenna in the atmosphere, and then converted back into a picture that we can see. The introduction of television revolutionized home life at the time and fundamentally changed the way people consumed information.
Television has evolved in different ways, depending on how radio waves are transmitted to the television screen. Starting with black-and-white televisions in the early 1950s-70s, followed by color televisions (brown tubes) in the 1980s, and LCD, LED, and PDP televisions in the 1990s and beyond, the picture quality and features have improved dramatically with technological advances. The development of television began in earnest when German physicist Karl Ferdinand Braun (1850 ~ 1918) developed the cathode ray tube (CRT), commonly known as the “Braun tube”. Braun’s tube utilized the principle of firing cathode rays from an electron gun, which, when deflected by a coil, hit a glass surface painted with a fluorescent material, causing it to glow, and like film movies, it exploited a feature of visual perception.
The “flip book” is also based on this principle. In other words, when you quickly flip through a book with your thumb, the illustrations appear as a movie. This phenomenon was long thought to be due to images remaining on the retina, but it’s actually caused by the stimulation of certain parts of the retina that specialize in detecting motion. As the Lumière brothers, who made the first movie in 1895, understood, a continuous sequence of images gives the impression of movement. This is the same principle behind the succession of images on television.
Color television uses cathode ray tubes just like black-and-white television, but the difference is in the way our eyes perceive color. Our retina analyzes colors through receptors called cones, which are sensitive to three colors: red, green, and blue. Mixing these three colors produces a wide range of colors, and the colors on your television screen are based on this principle. The screen of a television set is made up of hundreds of thousands of pixels, each of which is made up of three subpixels that emit red, green, and blue light. This makes it possible to reproduce all colors, and as a result, our eyes are able to detect a wide range of colors.
Currently, brown tube televisions have become increasingly expensive to produce due to the large front and back footprint of larger screen sizes, so LCD, LED, and PDP televisions, which are flat panel display televisions, began to be commercialized in the 2000s. Liquid crystal display (LCD) televisions work in a similar way to the liquid crystal devices used in portable electronic watches and wristwatches. The technology uses liquid crystal particles that reflect light in response to electrical signals to make up the screen, which is illuminated by a backlight behind the panel.
Light emitting diode (LED) televisions are similar to LCD televisions, but they use diodes, which are light-emitting devices, as the backlight. This technology is highly efficient, using less power, but it’s a bit more expensive and, like LCDs, can be prone to screen dragging. OLED (Organic Light Emitting Diodes) televisions differ from LEDs by using organic materials that are self-illuminating, eliminating the need for a backlight. This allows for thinner, lighter designs and lower power consumption, but difficulty in scaling and lifespan issues have limited their commercialization.
Plasma Display Panel (PDP) televisions use the principle of gas discharge using plasma gas to display the screen. This method is excellent in response speed, viewing angle, and color, but it has the disadvantages of heavy weight and high power consumption. It also generates heat from the gas discharge, which limits its efficiency.
The evolution of televisions is not just limited to changes in screen technology. Smart TVs, which have been around since the 2010s, have expanded their functionality beyond just receiving broadcasts to include browsing the internet, running apps, and playing an important role in smart home environments. Televisions have become more than just a viewing device; they are now the main media hub in the home, providing a wide range of entertainment such as live streaming, video calls, and online gaming over an internet connection.
The televisions of the future are expected to go beyond simply improving upon current capabilities to further transform the user experience by combining artificial intelligence (AI) and the Internet of Things (IoT). For example, AI-powered personalized content recommendations and voice-activated control systems will make television more convenient and intelligent. The introduction of holographic technology will also allow for a more immersive viewing experience, evolving the television from a simple video playback device to a window into the world, blurring the lines between reality and virtuality.
