Method of switching guest-host dual frequency liquid crystal by using back flow
Provided are methods of switching guest-host dual frequency liquid crystals by using a back flow. In the case of a shutter having a dual frequency liquid crystal layer between two transparent substrates, such a method includes: applying a first voltage having a first frequency to the dual frequency liquid crystal layer; and applying a second voltage having a second frequency to the dual frequency liquid crystal, the second frequency being higher than the first frequency, wherein the second voltage is higher than a threshold voltage that generates a back flow around liquid crystals of the dual frequency liquid crystal layer, and the first voltage is lower than the threshold voltage.
1. A method of switching dual frequency liquid crystals of a shutter having a dual frequency liquid crystal layer between two transparent substrates, the method comprising:
applying a first voltage having a first frequency to the dual frequency liquid crystal layer such that the dual frequency liquid crystals are switched to a homeotropic state; and
applying a second voltage having a second frequency to the dual frequency liquid crystal, the second frequency being higher than the first frequency, such that the dual frequency liquid crystals are switched to a 360° twisted state due to a back flow generated around the dual frequency liquid crystals,
wherein the second voltage is higher than a threshold voltage that generates a back flow around liquid crystals of the dual frequency liquid crystal layer, and
the first voltage is lower than the threshold voltage.
2. The method of claim 1 , wherein the dual frequency liquid crystal layer comprises an optical absorption dye.
3. The method of claim 1 , wherein the first voltage has a form of a square wave.
4. The method of claim 1 , wherein the second voltage has a form of a sine wave.
5. A method of switching dual frequency liquid crystals of a shutter having a dual frequency liquid crystal layer between two transparent substrates, the method comprising:
changing a state of the dual frequency liquid crystal layer so that an optical transmission of the dual frequency liquid crystal layer is increased; and
twisting the dual frequency liquid crystal layer 360° by generating a back flow around the liquid crystals of the dual frequency liquid crystal layer.
6. The method of claim 5 , wherein the changing of the state of the dual frequency liquid crystal layer comprises changing liquid crystals of the dual frequency liquid crystal layer from a horizontal state to a homeotropic state.
7. The method of claim 5 , wherein the back flow is generated by applying a voltage to the dual frequency liquid crystal layer that is greater than a threshold voltage that generates a back flow.
8. A method of switching dual frequency liquid crystals of a shutter having a dual frequency liquid crystal layer between two transparent substrates, the method comprising:
applying a first voltage having a first frequency to the dual frequency liquid crystal layer such that the dual frequency liquid crystals are switched to a homeotropic state; and
applying a second voltage having a second frequency to the dual frequency liquid crystal such that the dual frequency liquid crystals are switched to a 360° twisted state due to a back flow generated around the dual frequency liquid crystals,
wherein the second voltage is higher than a threshold voltage that generates a back flow around liquid crystals of the dual frequency liquid crystal layer and the first voltage is lower than the threshold voltage.
9. The method of claim 8 , wherein the second frequency is higher than the first frequency.