We always hear LCD, LED, OLED and AMOLED, but what is the principle of these four? And what's the differences between LED and LCD, LED and OLED, AMOLED and OLED?
1. Differences between LED and LCD
The full name of LCD is "Liquid Crystal Display". As a substitute for CRT display, its lightweight and cheap characteristics are the two most important factors that occupy the market. The LED refers to the backlight source of the LCD, before the OLED is listed, the LCD panel itself can not glow and need backlight support, this and the advertising box on the street is a working nature, the content on the light box can not be seen at night, can only be seen inside the light box.
In fact, many people have a misunderstanding that LCD and LED are two kinds of LCD screens, but this is not the case.
According to the difference of "backlight", LCD can be divided into "CCFL display" (cold cathode fluorescent lamp) and "LED display" (light emitting diode). If it is distinguished according to the "working principle", LCD can be divided into TN-LCD, TFT-LCD, STN-LCD and FSTN-LCD, etc., and the main difference between them lies in the "twisting angle of liquid crystal molecules". At present, most of the mainstream LCD displays on the market are products like TFT-LCD, and the others are relatively few.
In other words, LCD contains LED, and the full name of LED should be "LED backlit LCD screen". Compared with CCFL, it has the advantages of "small size" and "low power consumption". It achieves "higher brightness" while taking into account both thinness and lightness, but it is slightly inferior in color performance, so in professional drawing LCD, traditional CCFL is mostly used as backlight source.
2. Differences between LED and OLED
LED is the abbreviation of light emitting diode; OLED refers to the abbreviation of Organic Light-Emitting Diode.
a. the glowing principle of LED screen is different from that of OLED screen. The LED panel has a light-emitting layer, which is composed of several red light-emitting diodes, which uses the molecular deflection of the liquid crystal layer to show different images; each pixel of OLED can emit monochromatic light, so it does not need the light-emitting layer, but can directly drive the organic film to emit light by current.
b. the structure of the LED screen is different from that of the OLED screen. The structure of the LED screen is more complex, but it is composed of several layers; but the OLED is very thin because it does not need backlight, so the OLED screen is about 1/3 of the thickness of the LED screen, or even thinner; the OLED panel also has a bendable feature, which is completely impossible for the LED panel to do.
c. The display effect of LED screen is different from that of OLED screen. The LED screen can generally achieve 72% of the color gamut of NTSC, while the color of OLED is more conspicuous, reaching NTSC 100%, which can meet the needs of the more demanding color gamut such as BT 2020, but there may be problems of color temperature and color deviation.
d. LED screens have a longer life than OLED screens. There is no burning screen on the LED screen, and it is easy to burn the screen if the OLED screen has been used for a long time, and LED has more advantages in terms of service life.
3. Differences between AMOLED and OLED
AMOLED originated from OLED display technology, and it is also an extension of OLED technology. It can be said that AMOLED belongs to OLED, but OLED does not belong to AMOLED. In addition, the two are also different in the field of active luminescence control and application.
The main materials used for AMOLED screens and OLED screens are different. The AMOLED screen is a screen based on AMOLED material, while the OLED screen uses a very thin organic coating and glass substrate (or flexible organic substrate) that glows as the current passes through.
In addition, the AMOLED screen has the characteristics of faster response, higher contrast and wider viewing angle. The OLED display screen can be made lighter, thinner, with a larger viewing angle, and can greatly save power consumption.