1, LCD

LCD is short for Liquid Crystal Display in English, There are mainly TFT, UFB, TFD, STN and other types. Its structure includes plastic ball, glass ball, frame glue, glass substrate, upper polarizer, directional layer, liquid crystal, conductive ITO pattern, conduction point, IPO electrode and lower polarizer.

The principle of liquid crystal display is that liquid crystal will present different light characteristics under the action of different voltages. The liquid crystal display screen is composed of many liquid crystal arrays. In the monochrome liquid crystal display screen, a liquid crystal is a pixel (the smallest unit that can be displayed on the computer screen), in the color liquid crystal display screen, each pixel consists of red, green and blue liquid crystals. At the same time, it can be considered that there is an 8-bit register behind each liquid crystal, and the value of the register determines the brightness of each of the three liquid crystal units, however, the value of the register does not directly drive the brightness of the three liquid crystal units, but is accessed through a “palette. It is unrealistic to equip each pixel with a physical register. In fact, only one line of registers is equipped. These registers are connected to each line of pixels in turn and loaded into the contents of this line, drive all pixel lines to display a complete picture.

2, LED

LED is short for Light Emitting Diode. It is a kind of semiconductor diode, which can convert electric energy into light energy. When electrons are compounded with holes, visible light can be radiated, so it can be used to make light emitting diodes. Like common diodes, light emitting diodes are composed of a pn junction and also have unidirectional conductivity.

Its principle when the positive voltage is added to the light emitting diode, the holes injected into the N area from the P area and the electrons injected into the P area from the N area, within a few microns near the PN junction, it is compounded with electrons in N region and holes in P region respectively to generate spontaneous emission fluorescence. The energy states of electrons and holes in different semiconductor materials are different. When electrons and holes compound, the amount of energy released is different. The more energy released, the shorter the wavelength of the emitted light. Commonly used are diodes that emit red light, green light or yellow light.

LED is called Fourth generation Light Source, which has the characteristics of energy saving, environmental protection, safety, long service life, low power consumption, low heat, high brightness, waterproof, miniature, shockproof, easy dimming, concentrated light beam, simple maintenance, etc, it can be widely used in various fields such as indication, display, decoration, backlight, general lighting, etc.

Differences

1, On the color gamut

At present, the color gamut of LCD screen is between 72 and 92 percent, while that of led screen is above 118 percent. 

2, In terms of price

LED screens of the same size are more than twice as expensive as LCD screens

3, In terms of mature technology

Because LCD screen is a traditional display, it is much better than LED screen in terms of mature technology, such as display reaction speed, LED screen is far less than LCD screen.

4, In terms of the angle of the display

The specific manifestation is that the visual angle of the LCD screen is very small, while the LED screen is not satisfactory in layering and dynamic performance, in addition, the depth of the LED screen is not good enough.