Patent ID: 6078556
Filing Date: 2000-06-20
Classification: G11B

Abstract:
A system for producing a driving signal for a liquid crystal panel, for correcting a wavefront aberration in an optical system for an optical disc, the liquid crystal panel having a plurality of unit electrodes, the system comprising:control means for producing a control signal;a modulated signal generator for producing a modulated signal modulated in pulse width by the control signal from the control means;the modulated signal having a predetermined duty ratio based on the control signal;a frequency divider for dividing the modulated signal;selector means responsive to the modulated signal for selecting an output signal of the frequency divider and an intermediate level between a higher potential and a lower potential thereby producing a liquid crystal driving signal having the duty ratio based on the modulated signal;the control means being provided for producing the control signal for setting the duty ratio in accordance with a refractive index at each of the unit electrode of the liquid crystal panel.