Electric-field-driven LC lens for 3-D/2-D autostereoscopic display

The use of an electric-field-driven liquid-crystal (ELC) lens cell for switching between a 3-D and 2-D display is proposed. Due to the phase retardation of the non-uniform LC directors, an ELC lens functions the same as a geometric lens. The parameters of an ELC for 3-D applications are optimized through the simulation of the electrode configuration and voltage levels. A prototype was made where the ELC lens is placed in front of a liquid-crystal display (LCD) 15 in. on the diagonal with a 99-mu m subpixel pitch. Under zero voltage, the ELC lens is a transparent medium and the users can see a clear 2-D image. In 3-D mode, the ELC lens array performs the same as a cylindrical lens array to the incident vertical polarization under suitable driving voltages. Placing a half-wave plate between the LCD and ELC lens is proposed to change the polarization of the LCD to be parallel with the polarization lens direction of the ELC lens. The measurement of the horizontal luminance profile, performance of the ELC lens, and feasibility for 3-D/2-D switching was verified. The fabrication process for the ELC lens is compatible with the current LCD production process and enables the accurate control of the lens pitch of the ELC lens.