Design of LCD display system for handheld devices based on Linux

摘要

Nowadays handheld devices are oriented to equip with a colorful graphic user interface and be able to handle multiple tasks. These require the device to assembly of a TFT(Thin Film Transistor) LCD (Liquid Crystal Display) screen and be embedded with operation systems. Obviously these will increase the cost of the device. Especially if it runs on commercial embedded systems such as Windows CE, the cost will be higher. Also the power will be exhausted sooner. Then the problem of endurance will be more aggravate, since the handheld device is battery-powered. Therefore a good power management is required. This paper introduced a scheme of LCD display system based on Linux. It makes use of a LCD display module which is 38.78mm high and 30.62mm wide as the screen and an ARM(Advanced RISC Machines) core mcu(Micro Controller)-s3c2450 as the controller. Based on the power saving consideration, the system supports three operating modes — display off, standby, display on. LCD backlight as the most power-hungry component could be adjusted by duty-ratio of PWM(Pulse Width Modulation). The features of small size, simple structure, and good power management make it suitable for handheld devices.