What is The Differences Among LCD LED OLED QLED？

1. LCD

LCD is the full name of Liquid Crystal Display, which mainly includes several types of liquid crystal displays such as TFT, UFB, TFD, and STN, is the most widely used display technology.

The structure of LCD is to place a liquid crystal cell in two parallel glass substrates, a TFT (thin film transistor) is arranged on the glass of the lower substrate, and a color filter is arranged on the glass of the upper substrate, and the liquid crystal molecules are controlled by the signal and voltage change on the TFT Rotate the direction, so as to control whether the polarized light of each pixel is emitted or not to achieve the display purpose

LCD is a substance between solid state and liquid state. It cannot emit light by itself, and it needs an additional light source. Therefore, the number of lamps is related to the brightness of the liquid crystal display.

2. LED

LED (Light-emitting diode) screen, in fact, the images of these displays are still produced by liquid crystal, and the light-emitting diodes are only used as light sources. Technically, they are still LCD displays, or LED-backlit LCD display.

Liquid crystal (LCD) TV with LED screen has the advantages of small size, low power consumption, long lifespan, low cost, high brightness, wide viewing angle and high refresh rate. The disadvantage is that the color performance is relatively poor, especially when the LCD screen is folded. where the color deviation is more obvious.

3. OLED

OLED (Organic Light-Emitting Diode) Organic Light Emitting Diode.OLEDs can emit light by themselves, so there is no need for a backlight. LEDs use metal materials, while OLEDs use organic materials. They can emit light without lighting, and the contrast is better. 

The organic phosphorous materials used in OLED are relatively fragile, and the brightness will decrease after long-term use. Of course, the brightness of LCD will gradually decrease after long-term use.

4. QLED

QLED, short for Quantum Dot Light Emitting Diodes, is a self-illuminating technology that does not require additional light sources.

Quantum Dots are some extremely tiny semiconductor nanocrystals that cannot be seen by the naked eye, and are particles with a particle size of less than 10 nanometers. Quantum dots have a distinctive feature: whenever they are stimulated by light or electricity, they emit colored light. The color of the light is determined by the material and size of the quantum dot, and its frequency can be changed by changing the size of the quantum dot. , shape and material to precisely adjust for a variety of applications.

The structure of QLED is very similar to OLED technology, the main difference is that the light-emitting center of QLED is composed of quantum dots. Its structure is that electrons and holes on both sides converge in the quantum dot layer to form Exciton, and emit light through the recombination of photons.