An LED is a semiconductor diode that emits light when voltage is applied.
The expression light-emitting diode in the English language, which can be translated as “light-emitting diode” , gave rise to the acronym LED . Due to its widespread use, this acronym became a noun accepted by the Royal Spanish Academy ( RAE ) in its dictionary.
An LED is a semiconductor diode that, when energized, generates light. A diode , in turn, is a two-electrode valve that allows the passage of electric current in a single direction.
The LED and the emission of photons
It can be said that an LED is a light source . When voltage is applied to one of its two terminals, the recombination of its electrons causes the release of energy in the form of photons.
The color of the light produced by an LED is linked to the energy of the photons it emits, related to the so-called bandgap of the semiconductor. Currently LEDs cover wavelengths of the infrared spectrum, the ultraviolet spectrum and the visible spectrum .
Compared to fluorescent or incandescent light sources , LEDs are more convenient since they have a longer lifespan, consume less energy and are smaller. That is why they are used in multiple products and even in home lighting.
An LED television uses these diodes to backlight the screen.
From lamps to televisions
LED lamps , therefore, enjoy an increasingly important space in the market. As its intensity is lower compared to fluorescent lamps and incandescent lamps, it is common for an LED lamp to include several diodes.
An LED television , on the other hand, is one that uses LEDs to backlight the screen . There are devices that use white LEDs and others that use red, green and blue (RGB) LEDs.
Differences between an LED TV and an LCD
Although the LED television is considered an evolution of the LCD , and it is in a certain sense, the most relevant difference is the type of back lighting, since both use a liquid crystal screen in one of its several layers. To be more precise, the part that differentiates both types of television is the one that is furthest from the user, and that is why there is no visibly innovative element until we compare the image quality .
Televisions with liquid crystal displays stood out at the time for their division into pixels , which are the smallest unit in which they can represent a part of the image. Each of these, which are squares, can reproduce one of many colors, with a particular intensity. The problem with the first televisions was that the backlight covered large portions of the screen, and therefore scenes with small, highly contrasting elements were not seen correctly.
Let's imagine that we want to show a dark sky with bright stars; If there are two large fluorescent lamps in the background, it will be impossible to generate adequate contrast . Thanks to LED technology, companies include an increasing number of small lamps that, in premium models, can be turned on and off independently, allowing a much more faithful reproduction of a scene like this.
In addition to the increase in contrast and, consequently, in image quality, televisions with LED technology consume much less electrical energy than traditional LCDs. As if this were not enough, they are considerably thinner since small LED lamps take up less space than fluorescent ones.
Another advantage that sometimes goes unnoticed is its performance in rooms where it is impossible to turn off all the lights or achieve a good level of darkness, since the images of an LED television achieve a greater intensity than LCD ones and can cope without problem with the excessive ambient light .