An LCD controller is an integrated circuit chip or module used to control the operation of liquid crystal displays (LCD). The following is a detailed introduction from the aspects of functionality, working principle, and interfaces:
Main Functions
•Signal Conversion: Converts digital signals output by computers or other devices into signal formats suitable for LCD display, such as converting parallel data to serial data, or converting RGB signals into specific LCD drive signals.
•Timing Control: Generates precise timing signals to control various working stages of the LCD, including row scanning, column driving, data transmission, etc., ensuring correct image display and stable refresh.
•Data Processing: Processes input image data, such as grayscale conversion, color space conversion, contrast adjustment, brightness adjustment, etc., to optimize image quality.
Working Principle
•Display Data Storage: Typically includes display data memory (VRAM), used to store image data that will be displayed on the LCD.
•Drive Signal Generation: Generates corresponding drive signals based on the data stored in VRAM, controlling the orientation of liquid crystal molecules to change the transmission and blocking of light, thereby displaying different colors and brightness to form images.
Interface Types
•Parallel Interface: Data is transmitted in parallel, which is fast but requires more pins, commonly used in situations where display speed is critical, such as some industrial control displays.
•Serial Interface: Data is transmitted serially, requiring fewer pins, simpler wiring, and lower cost, commonly used in small LCD modules, such as mobile phone screens.
Common LCD Controller Chips
•ILI9341: Widely used in medium to small size TFT-LCD displays, supports multiple interfaces, can display 24 bit true color images, and has rich register settings for flexible display parameter configuration.
•SSD1306: Mainly used for OLED displays, but there are also some compatible versions for LCD. It uses I²C or SPI interfaces, has low power consumption, and is suitable for applications with strict power requirements, such as smartwatches and small handheld devices.
The LCD controller is the core component of the LCD display system, and its performance and functionality directly affect the display quality and application range of the LCD. Different types and specifications of LCD require corresponding LCD controllers to achieve optimal display performance.