Liquid crystal display device having a power saving function

A liquid crystal display device having a power saving function, comprising:

• a central processing unit for producing data signals when the display device is in an on-condition and for producing a power down signal when the display device is in an off-condition;
• a liquid crystal driver controller coupled to the central processing for receiving an input voltage and divided voltages and for producing a first voltage, segment-output signals and common-output signals when the central processing unit produces the data signals, and for producing a second voltage and direct current voltages when the central processing unit produces the power down signal, wherein the first voltage is higher than the second voltage in magnitude;
• a voltage divider coupled to the liquid crystal driver controller for receiving and dividing the first and second voltages and for supplying the divided voltages to the liquid crystal driver controller;
• a liquid crystal display panel coupled to the liquid crystal driver controller for receiving the segment-output signals and common-output signals to display the data signals of the central processing unit and for receiving the direct current voltage when the central processing unit produces the power down signal;
• a clock signal generator producing a clock signal and a disable clock signal when the power down signal is sent to the clock signal generator;
• and
• a DC to DC converter coupled to the clock signal generator for amplifying the input voltage according to the clock signal, wherein the DC to DC converter is disabled if the disable clock signal is sent to the DC to DC converter.