**1. OLED screen**

OLED screen, also known as organic light-emitting diode screen, is a self luminous screen that does not require a backlight source. OLED screens have advantages such as self illumination, high contrast, and vivid colors, and can also be made very thin, making them very popular in mobile phone design. However, OLED screens also have some drawbacks, such as relatively short lifespan and susceptibility to screen burn-in.

The working principle of OLED screens is to utilize the characteristic of organic materials emitting light under the action of current. When current passes through organic materials, the materials emit light, thereby achieving image display. Each pixel of an OLED screen emits light independently, allowing for high contrast and high saturation color display. Meanwhile, OLED screens also have the advantages of fast response speed and low power consumption, making them very suitable for displaying dynamic images and videos.

The advantages of OLED screens also include:

-Thin and light: OLED screens do not require a backlight and can be made very thin, making them very suitable for portable devices such as smartphones.

-High contrast: OLED screens have a very high contrast ratio, reaching 100000:1 or more, allowing them to display very deep black and bright colors.

-Wide viewing angle: OLED screens have a very wide viewing angle, reaching over 180 degrees, so the color and contrast of the image will not change when viewed from different angles.

The drawbacks of OLED screens include:

-Relatively short lifespan: The organic materials of OLED screens have a relatively short lifespan and are prone to screen burn-in, which means that when the same image is displayed for a long time, traces will be left on the screen.

-High cost: The production cost of OLED screens is relatively high, so the price is also relatively expensive.

-Insufficient brightness: OLED screens have relatively low brightness, which may make it difficult to see the screen content clearly in sunlight.

**2. LCD screen**

LCD screen, also known as liquid crystal display screen, is a type of screen that requires a backlight source. LCD screens have the advantages of low cost, high brightness, long lifespan, and also have good performance in color reproduction and contrast. However, LCD screens also have some drawbacks, such as relatively slow response speed and smaller viewing angles.

The working principle of LCD screens is to control the transmittance of light by utilizing the orientation changes of liquid crystal molecules under the action of an electric field. When an electric field acts on liquid crystal molecules, they undergo orientation changes, thereby altering the transmittance of light and achieving image display. The backlight source of LCD screens usually uses LED or CCFL (cold cathode fluorescent lamp), which can provide uniform brightness distribution.

The advantages of LCD screens include:

-Low cost: The production cost of LCD screens is relatively low, so the price is also relatively cheap.

-High brightness: LCD screens have relatively high brightness, and the screen content can be seen clearly in sunlight.

-Long lifespan: LCD screens have a relatively long lifespan and are less prone to screen burn-in.

The disadvantages of LCD screens include:

-Relatively slow response speed: LCD screens have a relatively slow response speed and may experience ghosting when displaying dynamic images.

-Small viewing angle: LCD screens have a relatively small viewing angle, and when viewed from different angles, the color and contrast of the image will change.

-Relatively low contrast: LCD screens have relatively low contrast and cannot display very deep black and bright colors.

**3. AMOLED screen**

AMOLED screen, also known as active matrix organic light-emitting diode screen, is a self luminous screen similar to OLED screen. AMOLED screens have the advantages of fast response speed, high contrast, vivid colors, and can also be made very thin, making them very popular in mobile phone design. However, AMOLED screens also have some drawbacks, such as relatively short lifespan and susceptibility to screen burn-in.

The working principle of AMOLED screens is to utilize the characteristic of organic materials emitting light under the action of current. When current passes through organic materials, the materials emit light, thereby achieving image display. Each pixel of an AMOLED screen emits light independently, allowing for high contrast and high saturation color display. Meanwhile, AMOLED screens also have the advantages of fast response speed and low power consumption, making them very suitable for displaying dynamic images and videos.

The advantages of AMOLED screens include:

-Fast response speed: AMOLED screens have a very fast response speed, reaching microsecond level, making them very smooth when displaying dynamic images.

-High contrast: AMOLED screens have a very high contrast ratio, reaching 100000:1 or more, allowing them to display very deep black and vibrant colors.

-Wide viewing angle: AMOLED screens have a very wide viewing angle, reaching over 180 degrees, so the color and contrast of the image will not change when viewed from different angles.

-Thin and light: AMOLED screens can be made very thin, making them very suitable for portable devices such as smartphones.

The drawbacks of AMOLED screens include:

-Relatively short lifespan: The organic materials of AMOLED screens have a relatively short lifespan and are prone to screen burn-in, which means that when the same image is displayed for a long time, traces will be left on the screen.

-High cost: The production cost of AMOLED screens is relatively high, so the price is also relatively expensive.

-Insufficient brightness: The brightness of AMOLED screens is relatively low, and it may be difficult to see the screen content clearly in sunlight.

**4. TFT screen**

TFT screen, also known as thin-film transistor screen, is a type of screen that requires a backlight source. TFT screens have the advantages of fast response speed, high brightness, high contrast, and also have good performance in terms of viewing angle. However, TFT screens also have some drawbacks, such as inaccurate color reproduction and smaller viewing angles.

The working principle of TFT screen is to use thin film transistors (TFT) to control the brightness of each pixel. TFT is a semiconductor device that can control the brightness of pixels by changing the current. When current passes through TFT, TFT controls the brightness of pixels, thereby achieving image display. The backlight source of TFT screens usually uses LED or CCFL (cold cathode fluorescent lamp), which can provide uniform brightness distribution.

The advantages of TFT screens include:

-Fast response speed: TFT screens have a very fast response speed, reaching the millisecond level, making them very smooth when displaying dynamic images.

-High brightness: The TFT screen has relatively high brightness, and the screen content can also be seen clearly in sunlight.

-High contrast: TFT screens have relatively high contrast and can display very deep black and bright colors.

-Wide viewing angle: TFT screens have a relatively wide viewing angle, reaching over 160 degrees, so the color and contrast of the image will not change when viewed from different angles.

The disadvantages of TFT screens include:

-Color reproduction is not accurate enough: The color reproduction of TFT screens is not accurate enough, which may result in color cast.

-High power consumption: TFT screens have relatively high power consumption, which can affect the battery life of the phone.

-High cost: The production cost of TFT screens is relatively high, so the price is also relatively expensive.