Dual display liquid crystal display device

1. A method for operating a dual display liquid crystal display (LCD) device, the method comprising the steps of:

converting light from a front light unit, into a linearly polarized light;

passing the linearly polarized light through an LCD panel, and controlling a linear polarization state of the light passing through the LCD panel depending on whether a voltage is applied to the LCD panel; and

selectively reflecting/transmitting the light with a selective reflection/transmission part depending on the circular polarization state of the light that has passed through the LCD panel;

wherein the selective reflection/transmission part selectively reflects the light in a reflection mode to display an image on a front side thereof in a first display mode; and

wherein the selective reflection/transmission part passes the light in a transmission mode to display an image on a rear side thereof in a second display mode.

2. The operating method of claim 1 , wherein the selective reflection/transmission part comprises:

a cholesteric liquid crystal (CLC) film that selectively transmits light having a first circular polarization and reflects light having a second circular polarization, wherein the first and second circular polarizations have opposite directions;

a first phase compensation film at the front of the CLC film that generates a phase difference of about λ/4 with respect to the light; and

a second phase compensation film at the rear of the CLC film, for generating a phase difference of λ/4 with respect to the light.

3. The operating method of claim 1 , wherein the first phase compensation film and the second phase compensation film are composed of a quarter wave plate (QWP).

4. The operating method of claim 1 , wherein an angle between the optical axes of the first phase compensation film and the second phase compensation film is about 90°.