Scan driving method for high-quality image and cholesteric liquid-crystal display device using the same

A display device, comprising:

• a display panel, comprising:
• a first substrate on which a plurality of first electrodes extending in a first direction are formed;
• a second substrate on which a plurality of second electrodes extending in a second direction different from the first direction are formed;
• a cholesteric liquid-crystal layer formed between the first substrate and the second substrate;
• and
• a driving circuit section, configured to apply a plurality of alternating-current (AC) voltage pulses to pixel circuits at intersections between the first electrodes and the second electrodes,
• wherein the driving circuit section is further configured to perform a full screen reset procedure to the display panel, which is followed by a pulse-width modulation (PWM) scanning procedure, to control cholesteric molecules within the pixel circuits to enter a focal conic state, wherein:
• the full screen reset procedure comprises a first reset phase and a second reset phase arranged in sequence;
• the cholesteric molecules within the pixel circuits enter a homeotropic state during the first reset phase, and enter the focal conic state during the second reset phase;
• a plurality of first AC voltage pulses with a first voltage amplitude are applied to the pixel circuits during the first reset phase;
• and
• a differential voltage sensed by the cholesteric molecules within the cholesteric liquid-crystal layer at an end of the first reset phase equals to a positive first voltage with the first voltage amplitude.