LCD having switchable viewing angles

1 . A liquid crystal display (LCD) having switchable viewing angles, the LCD comprising:

a first and a second substrates;

a liquid crystal layer disposed between the first and the second substrates; and

a light source;

wherein the liquid crystal layer has a phase retardation with a predetermined range of value more than wavelength of light produced from the light source.

2 . The LCD as claimed in claim 1 , wherein the LCD displays a first state when a applied voltage is V 1 or V 3 , and displays a second state when a applied voltage is V 2 , V 1 being less than V 2 , V 2 being less than V 3 , wherein the first and second states are a bright state or a dark state, but are different states.

3 . The LCD as claimed in claim 2 , wherein the LCD displays two dark states at V 1 and V 3 of the applied voltage, and one bright state at V 2 .

4 . The LCD as claimed in claim 2 , wherein the LCD displays two bright states at V 1 and V 3 of the applied voltage, and one dark state at V 2 .

5 . The LCD as claimed in claim 2 , wherein the LCD comprises a transmittance versus applied voltage curve (V-T curve), the V-T curve comprising at least a first region between V 1 and V 2 , and a second region between V 2 and V 3 .

6 . The LCD as claimed in claim 5 , wherein the V-T curve comprises two peaks and one trough, the LCD displays two bright states and one dark state.

7 . The LCD as claimed in claim 5 , wherein the V-T curve comprises two troughs and one peak, the LCD displays two dark states and one bright state.

8 . The LCD as claimed in claim 5 , wherein a viewing angle in the first region is different from a viewing angle in the second region.

9 . The LCD as claimed in claim 1 , wherein the predetermined range of value of the phase retardation is between about 500 to 900 nanometers.

10 . The LCD as claimed in claim 1 , wherein the phase retardation is determined by Δn·d, wherein the “d” represents a cell gap of a liquid crystal layer of the LCD, and the “Δn” represents a refractive index retardation of liquid crystal molecules of the LCD.

11 . The LCD as claimed in claim 1 , wherein the LCD comprises two bright states and two dark states.

12 . An electronic device, comprising:

an LCD as claimed in claim 1; and

an input is operatively coupled to the LCD and provides an output voltage powering the LCD to display images.

13 . A method of driving an LCD with switchable viewing angles, comprising:

providing an LCD, wherein the LCD displays a first state when the applied voltage is V 1 or V 3 , and displays a second state when the applied voltage is V 2 , V 1 being less than V 2 , V 2 being less than V 3 , wherein the first and second states are a bright state or a dark state, but are different states, wherein the LCD comprises a transmittance versus applied voltage curve (V-T curve), the V-T curve comprising at least a first region between V 1 and V 2 , and a second region between V 2 and V 3 ;

subjecting the LCD to display a first viewing angle by applying a first voltage in the first voltage range of V 1 to V 2 ; and

subjecting the LCD to display a second viewing angle by applying a second voltage in the second voltage range of V 2 to V 3 .

14 . The method as claimed in claim 13 , wherein the V-T curve comprises two peaks and one trough, and the first state is a bright state, the second state is a dark state.

15 . The method as claimed in claim 13 , wherein the V-T curve comprises one peak and two troughs, and the first state is a dark state, the second state is a bright state.

16 . The method as claimed in claim 13 , wherein the value of the phase retardation has a range of about 500 to 900 nanometers.

17 . The method as claimed in claim 13 , wherein the phase retardation is determined by Δn·d, wherein the “d” represents a cell gap of a liquid crystal layer of the LCD, and the “Δn” represents a refractive index retardation of liquid crystal molecules of the LCD, and the method further comprises a step of determining the phase retardation by adjusting the cell gap of the liquid crystal layer.