LCD (Liquid Crystal Display) Ekran LCD is a flat display device widely used in various devices such as televisions, computers, mobile phones, and tablet computers. It modulates the degree of light transmission by controlling the arrangement and steering of liquid crystal molecules to display images or text. LCD screens are deeply loved by consumers for their high definition, low power consumption, thinness and portability. So, how does the LCD screen work? This article will introduce the structure and working principle of LCD screen in detail.
Basic structure of LCD screen
LCD screen mainly consists of the following parts:
- Liquid crystal layer: The liquid crystal layer is composed of liquid crystal molecules. These liquid crystal molecules will rotate and change their arrangement under the action of an electric field, thus controlling the degree of light transmission.
- Backlight: The backlight provides a light source so that liquid crystal molecules can be illuminated. Common backlight sources include CCFL (Cold Cathode Fluorescent Lamp) and LED (Light Emitting Diode).
- Polarizer: The polarizer divides the incident light into two directions, so that the light can only pass through one direction of the liquid crystal layer.
- TFT matrix: The TFT matrix is used to control the arrangement and steering of liquid crystal molecules. It is composed of a large number of transistors. The arrangement of liquid crystal molecules can be controlled by controlling the switching of the transistors.
- Color filter: Color filter is used to produce color images. It consists of filters of three colors: red, green, and blue. Different colors can be produced by controlling the transmission ratio of filters of different colors. s color.
Working principle of LCD screen
The working principle of LCD screen mainly includes the following steps:
- Image signal input: When the image signal is input to the LCD screen, it is first processed by the controller and converted into a signal that can be recognized by the drive circuit.
- Driving circuit operation: The source driver and the gate driver respectively control the pixels on the LCD panel according to the signals output by the controller. The source driver is responsible for controlling the brightness of the pixel, while the gate driver is responsible for controlling the switching state of the pixel.
- Liquid crystal molecule arrangement: Under the control of the drive circuit, the liquid crystal molecules will change their alignment direction according to changes in the electric field. When the electric field intensity is small, the liquid crystal molecules are arranged horizontally, and the light is completely blocked after passing through the polarizer; when the electric field intensity is large, the liquid crystal molecules are arranged vertically, and the light is partially transmitted after passing through the polarizer. By adjusting the electric field intensity at different pixels, the light can be controlled to display different images.
- Light transmission: The light emitted by the backlight passes through the light guide plate and is evenly illuminated on the LCD panel, and then passes through the action of the polarizer to form the image we see.
Advantages and disadvantages of LCD screen
LCD screens have the following advantages:
- High definition: The LCD screen has a high resolution and a clear display effect.
- Low power consumption: Compared with other display technologies, LCD screens have lower power consumption.
- Thin, light and portable: The LCD screen is thin, lightweight and easy to carry.
However, LCD screens also have some shortcomings:
- Limited viewing angle: The LCD screen has a relatively small viewing angle, and the image color and brightness will change when viewed from the side.
- Slow response speed: The response speed of the LCD screen is relatively slow and prone to smearing.
- Low color reproduction: The color reproduction of LCD screens is relatively low and cannot compete with new display technologies such as OLED.
In short, LCD screens occupy an important position in modern electronic devices due to their high definition, low power consumption, thinness and portability. Although there are some shortcomings, with the continuous development of technology, I believe that the performance of LCD screens will be further improved in the future.
