Liquid crystal display device having spontaneous polarization

A liquid crystal display device, comprising:

• two substrates facing each other;
• a liquid crystal material having a spontaneous polarization, placed between said substrates;
• electrodes for applying a voltage to said liquid crystal material;
• and
• a switching element connected to said electrodes,
• wherein said liquid crystal material exhibits a monostable state in which an average molecular axis of a liquid crystal molecular director is present in substantially one direction in the absence of an applied voltage,
• wherein, when a voltage of a first polarity is applied, the average molecular axis tilts from a monostable position to one side at an angle corresponding to a magnitude of the applied voltage,
• wherein, when a voltage of a second polarity having an opposite characteristic to the first polarity is applied, the average molecular axis maintains the monostable position or tilts from the monostable position to a side opposite to said one side corresponding to the application of the voltage of the first polarity,
• wherein, when a tilt angle in the application of the voltage of the first polarity is larger than a tilt angle in the application of the voltage of the second polarity, a maximum tilt angle in the application of the voltage of the first polarity is not less than 35°, and
• wherein a relation 2Ps·A>Q is satisfied, where Q is a maximum charge amount stored in each pixel by switching of said switching element, A is the area of said electrodes, and Ps is a magnitude of said spontaneous polarization per unit area.

A liquid crystal display device, comprising:

• two substrates facing each other;
• a liquid crystal material having a spontaneous polarization, placed between said substrates;
• electrodes for applying a voltage to said liquid crystal material;
• and
• a switching element connected to said electrodes,
• wherein said liquid crystal material exhibits a monostable state in which an average molecular axis of a liquid crystal molecular director is present in substantially one direction in the absence of an applied voltage,
• wherein, when a voltage of a first polarity is applied, the average molecular axis tilts from a monostable position to one side at an angle corresponding to a magnitude of the applied voltage,
• wherein, when a voltage of a second polarity having an opposite characteristic to the first polarity is applied, the average molecular axis maintains the monostable position or tilts from the monostable position to a side opposite to said one side corresponding to the application of the voltage of the first polarity,
• wherein, when a tilt angle in the application of the voltage of the first polarity is larger than a tilt angle in the application of the voltage of the second polarity, a maximum tilt angle in the application of the voltage of the first polarity is not less than 35°, and
• wherein a maximum charge amount stored in each pixel by switching of said switching element is smaller than a total charge amount of a switching current per pixel resulting from a complete reversal of the spontaneous polarization of said liquid crystal material.

A liquid crystal display device, comprising:

• two substrates facing each other;
• a liquid crystal material having a spontaneous polarization, placed between said substrates;
• electrodes for applying a voltage to said liquid crystal material;
• and
• a switching element connected to said electrodes,
• wherein said liquid crystal material exhibits a monostable state in which an average molecular axis of a liquid crystal molecular director is present in substantially one direction in the absence of an applied voltage,
• wherein, when a voltage of a first polarity is applied, the average molecular axis tilts from a monostable position to one side at an angle corresponding to a magnitude of the applied voltage,
• wherein, when a voltage of a second polarity having an opposite characteristic to the first polarity is applied, the average molecular axis maintains the monostable position or tilts from the monostable position to a side opposite to said one side corresponding to the application of the voltage of the first polarity,
• wherein, when a tilt angle in the application of the voltage of the first polarity is larger than a tilt angle in the application of the voltage of the second polarity, a maximum tilt angle in the application of the voltage of the first polarity is not less than 35°, and
• wherein, when charge amount injected in each pixel when the applied voltage is +V or −V is denoted by q, a charge amount of a current flowed by a response of said liquid crystal material due to the applied voltage of +V or −V is not more than q.