The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.