In recent years, televisions have evolved drastically in terms of technology. The most popular type of TV nowadays is the LED TV. It provides a crisp, clear image that can offer an immersive viewing experience. But how does an LED TV work?
An LED TV is essentially an LCD panel that uses LED lights as an illuminator. The LCD (Liquid Crystal Display) technology is the key element that produces an image on the screen. Polarization is a crucial concept in the production of a picture. It refers to the direction that the light wave oscillates or goes up and down.
Two filters are used in an LCD panel, and they are placed in front of the LED backlighting perpendicular to each other. Only vertically polarized light can get through the first filter, and no light is able to get to the second. But if no light can get through the screen, how do we see an image? This is where the liquid crystals come in.
Liquid crystals are complex molecules that are naturally twisted 90 degrees. When light strikes the crystals, it reflects around them, changing the polarization of the light. Now the light is able to get through the second screen as polarization has changed. The degree to which the liquid crystals are bent can be controlled by an electric field. With more voltage, they unbend, and in this way, the intensity of light emitted by the LCD can be controlled.
Each sub-pixel unit on the TV has its own electrode so that they can be controlled independently. For the most part, pixels contain three sub-pixels of different colors. A color filter is put over a sub-pixel to obtain the desired color, such as red, green, or blue. TVs have millions of sub-pixels that are all controlled in sequence to produce a picture.
By dimming the blue and green, red light is produced, and by dimming blue and red, green is produced. If more than one sub-pixel is on, then the eye blends the colors together to get a new color. For example, leaving red and blue sub-pixels on will give magenta. Each sub-pixel has 256 levels of brightness in most cases, and up to 16.7 million colors can be created by combining various levels of sub-pixel intensity.
In conclusion, an LED TV uses a combination of LCD technology and LED lights to produce a picture. Polarization is a key concept in the production of an image. The clever use of liquid crystals allows the degree of bending to be controlled by an electric field. This, in turn, controls the intensity of light emitted by the LCD. By controlling each sub-pixel independently, millions of colors can be created to produce a beautiful image on the screen.