In this blog post, we’ll explain the history and principles of technological advancements in television—from its inception to today’s smart TVs—in an easy-to-understand way.
Television (TV), one of the main electronic devices in our homes, refers to a telecommunications method that transmits optical images of objects via radio waves to be reproduced on a receiving device, or to the receiver that captures those images. In the word “television,” “tele” comes from the Greek word for “far,” and “vision” comes from the Latin word for “to see.” The principle behind this technology involves converting images transmitted from a broadcasting station into radio waves, receiving them via an antenna in the air, and then converting the signals back into images visible to the human eye. The introduction of television brought a major innovation to home life at the time and caused a fundamental shift in the way people consumed information.
Television has evolved in various ways depending on how radio waves are displayed on the screen. Starting with black-and-white televisions in the early 1950s to 1970s, it progressed to color televisions (CRT) in the 1980s, and then to LCD, LED, and PDP televisions in the 1990s and beyond, with picture quality and functionality improving significantly as technology advanced. The development of television began in earnest when German physicist Karl Ferdinand Braun (1850–1918) invented the cathode ray tube (CRT), commonly known as the “Braun tube.” The cathode ray tube operates on the principle of emitting electrons from a cathode gun, which are then deflected by coils to strike a glass screen coated with a phosphor, causing it to emit light. Like film-based cinema, it utilizes a specific characteristic of visual perception.
“Flip books” are also based on this principle. Simply put, when you quickly flip through the pages with your thumb, the illustrations appear to move like a video. This phenomenon was long believed to be caused by images lingering on the retina, but in fact, it occurs when specific areas of the retina—which are specialized for detecting motion—are stimulated. As the Lumière brothers, who created the first film in 1895, understood, a sequence of consecutive images gives the impression of movement. The principle behind the continuous flow of images on television is similar.
Color television operates on the same principle as black-and-white television, using a cathode ray tube, but the difference lies in how our eyes perceive color. Our retinas analyze color through receptors called cones, each of which is sensitive to one of three primary colors: red, green, and blue. Mixing these three colors reproduces a wide range of colors, and the colors on a television screen are based on this principle. A television screen consists of hundreds of thousands of pixels, and each pixel is made up of three subpixels that emit red, green, and blue light. This allows for the reproduction of all colors, and as a result, our eyes perceive a wide variety of colors.
Currently, as the screen size of CRT televisions increases, the space they occupy front and back grows rapidly, and production costs rise significantly. Consequently, flat-panel display televisions—such as LCD, LED, and PDP models—began to be commercialized in the 2000s. LCD (Liquid Crystal Display) televisions operate in a manner similar to the liquid crystal devices used in portable digital watches or wristwatches. This technology uses liquid crystal particles that reflect light in response to electrical signals to form the screen, and the screen is illuminated by a backlight located behind the panel.
LED (Light Emitting Diode) televisions are similar to LCD televisions, but they use light-emitting diodes as the backlight. While this technology boasts high efficiency with low power consumption, it has the drawbacks of being somewhat expensive and, like LCDs, prone to screen burn-in.
OLED (Organic Light Emitting Diodes) televisions differ from LEDs in that they use self-emissive organic materials, eliminating the need for a backlight. This allows for thinner and lighter designs and lower power consumption. However, commercialization is limited due to difficulties in scaling up to large sizes and concerns regarding lifespan.
PDP (Plasma Display Panel) televisions display images using the principle of gas discharge with plasma gas. While this method excels in response speed, viewing angles, and color reproduction, it has the drawbacks of being heavy and consuming a significant amount of power. Additionally, since heat is generated by the gas discharge, there are limitations in terms of efficiency.
The evolution of televisions is not limited to changes in display technology alone. Functional expansions, such as integration with smartphones and the internet, have also taken place. In particular, smart TVs, which emerged after the 2010s, go beyond simple broadcast reception to offer various functions such as internet searches and app execution, playing a crucial role in smart home environments. Today, televisions have evolved beyond mere viewing devices to become the primary media hub in the home, providing a wide range of entertainment options—such as real-time streaming, video calls, and online gaming—through internet connectivity.
Future televisions are expected to go beyond simply improving current functions; by combining artificial intelligence (AI) and the Internet of Things (IoT), they are anticipated to revolutionize the user experience. For example, personalized content recommendation features powered by AI and voice-recognition-based control systems will make using televisions even more convenient and smart. Furthermore, the introduction of hologram technology will enable a more immersive viewing experience, allowing televisions to evolve beyond mere video playback devices into gateways that blur the boundaries between reality and the virtual world.
