The backlight of a display screen consists of the following main components:

 

1. Light source: The light source of backlight usually uses cold cathode fluorescent lamp (CCFL) or LED lamp. These light sources produce high-brightness, uniform light that illuminates the entire display.

2. Reflective plate: The reflective plate is located between the light source and the LCD screen. It reflects the light from the light source and shines forward. A reflective plate is usually a piece of highly reflective material, such as white plastic or metal.

3. Diffuser film: Diffuser film is a layer of transparent material located between the reflective plate and the LCD screen. The function of the light leveling film is to disperse the light evenly and ensure that the light can pass through the LCD screen evenly.

4. LCD screen: The LCD screen is the core component of the display screen. It consists of a layer of liquid crystal, electrodes and a glass substrate. The LCD screen controls the transparency of each pixel and adjusts the passage of light according to the display signal to form an image.

5. Control circuit: The control circuit is responsible for adjusting the brightness and uniformity of the backlight. It controls the brightness of the light source according to the input signal and maintains the stability and uniformity of the backlight through a feedback mechanism.

Through the synergy of these components, the backlight system can provide sufficient brightness and uniform illumination so that the image on the LCD screen can be clearly seen. The design and quality of the backlight system have an important impact on the visual effect of the display.

 

Uneven display backlight may be caused by the following reasons:

 

1. Light source problem: The backlight of the display screen usually uses cold cathode fluorescent lamps (CCFL) or LED as the light source. If there are problems with the backlight source itself, such as aging, end of life, uneven brightness, or damage to the light emitting tube, it will cause uneven backlighting. This situation usually requires replacing the backlight module or light source.

2. Backlight module problem: The backlight module is one of the key components behind the display. If the number of light-emitting tubes or LEDs in the backlight module is uneven, the installation position is inaccurate, or there is a fault, it may cause uneven backlight. In this case, the backlight module needs to be replaced or adjusted to solve the problem.

3. Diffuser film problem: Diffuser film is a layer installed between the backlight and the LCD screen to disperse light evenly. If the light leveling film is damaged, aged, or installed incorrectly, it will cause uneven backlighting. Repairing the leveling film usually requires replacing the entire display assembly.

4. Circuit driver issues: The circuit driver board of the display screen is responsible for controlling the brightness and uniformity of the backlight. If the driver board is faulty, damaged or defective, it will have an impact on the backlight, resulting in uneven backlight. This situation usually requires repair or replacement of the driver board.

5. Structural design issues: The structural design of the display may also affect backlight uniformity. If the display design contains physical barriers or improper mounting between the backlight source and the LCD screen, uneven backlighting will result. Fixing this problem may require redesigning or replacing the display.

To sum up, the uneven backlight of the display screen may be caused by light source problems, backlight module problems, light uniformity film problems, circuit drive problems or structural design problems. In order to solve the problem of uneven backlight, it is necessary to diagnose the specific situation and take corresponding repair measures.