TFTs are Active-Matrix LCDs that have tiny switching transistors and capacitors. These tiny transistors control each pixel on the display and require very little energy to actively change the orientation of the liquid crystal in the display. This allows for faster control of each Red, Green, and Blue sub-pixel cell, thus producing clear, fast-moving, colorful graphics.
What's inside a TFT?
The transistors in the TFT are arranged in a matrix on the glass substrate. Each pixel on display remains off until addressed by applying a charge to the transistor.
Unlike conventional Passive-Matrix displays, in order to activate a specific pixel, the corresponding row is turned on, and a charge is sent down the proper column. Only the capacitor at the designated pixel receives a charge and is held until the next refresh cycle. Essentially, each transistor acts as an active switch. By incorporating an active switch, it limits the number of scan lines and eliminates cross-talk issues.
Inside a TFT Pixel
The pixels of the TFTs are divided into sub-pixels capable of producing various intensities of Red, Green or Blue. The mixture of color and levels of intensity allows for an accurate depiction of any combination of 16.7 million colors.