What is the difference between an OLED screen and an LCD screen?

Part 01

Pixel

To understand the difference between these two types of screens, we must first understand how images are displayed. If we look close to the screen, we will find many small dots, these are pixels. The images we usually see on the screen are made up of these tiny pixels. The pixel is composed of three different colors of red, green and blue. By adjusting the ratio of the three primary colors of red, green and blue, the desired color can be modulated within a certain range. And many pixels of different colors are put together to form the picture we see on the screen.

Part 02

Display principle

Although the two types of screens use pixels to piece together the picture, the principles of their pixels are not the same.

LCD

LCD, the abbreviation of Liquid Crystal Display, the Chinese full name is Liquid Crystal Display. An LCD screen emits white light from a whole backlight layer. After the white light passes through the color filter layer, it becomes one of the red, green, and blue colors set by the sub-pixels in that part. the liquid crystal layer. The liquid crystal layer can be deflected by applying a voltage, thereby controlling the brightness of the sub-pixels.

OLED

OLED, the abbreviation of OrganicLight-Emitting Diode, is called organic light-emitting diode in Chinese. Different from the light-emitting principle of LCD, it does not require the light-emitting layer to provide a light source, nor does it require the deflection of the liquid crystal layer to adjust the brightness. Instead, the organic self-luminous diode emits light to produce sub-pixels with different colors, which can be adjusted by adjusting how much power is applied to the diode. brightness. It can be understood that each sub-pixel is an independent small light, and the LCD screen is provided by a large light behind the backlight layer.

Part 03

Advantages and Disadvantages Analysis

Thickness

Because there is no backlight layer and liquid crystal layer, the thickness of the OLED screen is generally thinner than that of the LCD screen, which is one of the reasons why more and more manufacturers use OLED screens in today's mobile phones.

Show

OLED uses sub-pixels to emit light, which means that it does not emit light when it displays black. The LCD emits light for the backlight layer, and displays black by reducing the light transmitted by the liquid crystal layer. Therefore, theoretically, the LCD screen cannot display pure black, and the contrast ratio is generally not as high as that of the OLED screen. In addition, LCD also has a certain light leakage phenomenon.

Power consumption

The lighting of the LCD requires the backlight layer to emit light. As long as the screen is in use, the entire screen will be lit. The OLED screen only needs to make the screen in the corresponding position emit light. Therefore, under normal use, the power consumption of the LCD screen will be higher.

Durability

Since the OLED screen uses organic materials, it is not as stable as the inorganic materials of the LCD screen. In addition, unlike the whole lighting of the LCD screen, the partial lighting of the OLED screen when using it is destined to consume faster in some areas of the screen, and the brightness is lower than that of other parts, which is the phenomenon of "burning screen".

Plasticity

Because there is no liquid crystal layer and backlight layer, the OLED screen can achieve a large amount of bending, folding, etc., while the LCD can only achieve a curved screen on a larger screen. Therefore, all curved screen mobile phones and folding screen mobile phones currently on the market are OLED screens.

Eye protection

The LCD screen can directly adjust the brightness by controlling the voltage of the backlight layer, but the OLED will display unevenly due to low voltage, so the method of changing the screen flickering frequency with the brightness unchanged is adopted. (specifically, you can search for PWM dimming) and when the frequency is low, the human eye will feel uncomfortable, which is why many people prefer LCD screens. But at the same time, LCD generally emits in the blue light frequency band of 420-440, which is harmful to human eyes, so it is difficult to say which screen is more friendly to the eyes. The best way to protect eyes is always to look at mobile phones less.