Optical module and positioning frame thereof

A method for driving a liquid crystal display, the liquid crystal display including a plurality of pixels, each pixel being capable of displaying a plurality of gray levels, a first predetermined gray level signal determining a corresponding gray level for one of the plurality of pixels in a previous frame, a current frame following immediately after the previous frame, and a second predetermined gray level signal determining a corresponding gray level for the one of the plurality of pixels in the current frame, the method comprising:

• comparing the gray level associated with the second predetermined gray level signal to the gray level associated with the first predetermined gray level signal;
• applying a hold-type voltage to drive the pixel in the current frame if the gray level associated with the second predetermined gray level signal and the gray level associated with the first predetermined gray level signal are substantial the same;
• and
• applying an impulse-type voltage to drive the one of the plurality of pixels in at least one frame subsequent to the current frame if the gray level associated with the second predetermined gray level signal and the gray level associated with the first predetermined gray level signal are different, wherein the impulse-type voltage includes four impulse signals, and the four impulse signals are input in sequence to the pixel during the frame subsequent to the current frame.

A system for driving a liquid crystal display, the system receiving a video signal including a first predetermined gray level signal and a second predetermined gray level signal, the first predetermined gray level signal determining a corresponding displaying gray level for a pixel in a previous frame, the second predetermined gray level signal determining a corresponding displaying gray level for the pixel in a current frame subsequent to the previous frame, the system comprising:

• a memory for storing the first predetermined gray level signal;
• an impulse signal module for receiving the first predetermined gray level signal and the second predetermined gray level signal to generate a plurality of impulse signals;
• a first multiplexer for receiving the plurality of impulse signals and outputting the second predetermined gray level signal or the plurality of impulse signals according to the first control signal;
• and
• a detection unit for generating a first control signal to be applied to the first multiplexer according to whether the gray level associated with the first predetermined gray level signal and the gray level associated with the second predetermined gray level signal are substantial the same or not, for switching the impulse-type driving or the hold-type driving.