Driving method for liquid crystal electro-optical device

A driving method for a liquid crystal electro-optical element having a plurality of liquid crystal molecules that have two orientation states in a ferroelectric phase and one orientation state in an antiferroelectric phase, a first substrate having scanning electrodes, a second substrate having signal electrodes, said plurality of liquid crystal molecules sandwiched between opposing electrode surfaces of said first and second substrates, said method comprising the steps of:

• a) in a first time period of the selection period, applying to said liquid crystal molecules, a first voltage pulse for lining up the orientation direction of said liquid crystal molecules in one orientation state;
• b) in a second time period of the selection period, if the orientation state to be selected is an antiferroelectric phase, applying to said liquid crystal molecules, a second voltage pulse whose absolute value is less than a threshold value;
• c) in said second time period of the selection period, if the orientation state to be selected is a ferroelectric phase, applying to said liquid crystal molecules, a voltage pulse whose absolute value is larger than said threshold value;
• d) in a third time period of a non-selection period, applying to said liquid crystal molecules, a voltage pulse group for maintaining the orientation state selected in the second time period of said selection period;
• and
• e) in a fourth time period of the non-selection period, applying, to said liquid crystal molecules, a voltage pulse group whose absolute value is less than said threshold value independent of the orientation state selected in said second time period.

A driving apparatus for a liquid crystal electro-optical element having a plurality of liquid crystal molecules that have two orientation states in a ferroelectric phase and one orientation state in an antiferroelectric phase, a first substrate having scanning electrodes, a second substrate having signal electrodes, said plurality of liquid crystal molecules sandwiched between opposing electrode surfaces of said first and second substrates, said driving apparatus comprising driving means for:

• a) in a first time period of a selection period, applying to said liquid crystal molecules, a first voltage pulse for lining up the orientation direction of said liquid crystal molecules in one orientation state;
• b) in a second time period of the selection period, if the orientation state to be selected is an antiferroelectric phase, applying to said liquid crystal molecules, a second voltage pulse whose absolute value is less than a threshold value;
• c) in said second time period of the selection period, if the orientation state to be selected is a ferroelectric phase, applying to said liquid crystal molecules, a voltage pulse whose absolute value is larger than said threshold value;
• d) in a third time period of the non-selection period, applying to said liquid crystal molecules, a voltage pulse group for maintaining the orientation state selected in the second time period of said selection period;
• and
• e) in a fourth time period of the non-selection period, applying, to said liquid crystal molecules, a voltage pulse group whose absolute value is less than said threshold value independent of the orientation state selected in said second time period.

A liquid crystal display apparatus having a liquid crystal electro-optical element having a plurality of liquid crystal molecules that have two orientation states in a ferroelectric phase and one orientation state in an antiferroelectric phase, a first substrate having scanning electrodes, a second substrate having signal electrodes, said plurality of liquid crystal molecules sandwiched between opposing electrode surfaces of said first and second substrates, said liquid crystal display apparatus comprising driving means for:

• a) in a first time period of the selection period, applying to said liquid crystal molecules, a first voltage pulse for lining up the orientation direction of said liquid crystal molecules in one orientation state;
• b) in a second time period of a selection period, if the orientation state to be selected is an antiferroelectric phase, applying to said liquid crystal molecules, a second voltage pulse whose absolute value is less than a threshold value;
• c) in said second time period of the selection period, if the orientation state to be selected is a ferroelectric phase, applying to said liquid crystal molecules, a voltage pulse whose absolute value is larger than said threshold value;
• d) in a third time period of the non-selection period, applying to said liquid crystal molecules, a voltage pulse group for maintaining the orientation state selected in the second time period of said selection period;
• and
• e) in a fourth time period of the non-selection period, applying, to said liquid crystal molecules, a voltage pulse group whose absolute value is less than said threshold value independent of the orientation state selected in said second time period.