Patent ID: 10823990

Abstract:
A switchable view angle control device includes an electrically switchable zenithal bistable liquid crystal display view angle control liquid crystal device (ZBD view angle control LCD) that is operable in a first state and a second state; a front polarizer located on a viewing side of the switchable ZBD view angle control LCD; and a polarized light source located on a non-viewing side of the switchable ZBD view angle control LCD that emits light that is polarized in a first direction. When the switchable ZBD view angle control LCD in the first state, the view angle control device operates in a narrow angle view mode in which the polarization of the light from the polarized light source is changed by the switchable ZBD view angle control LCD to be polarized in a second direction that is at least partially absorbed by the front polarizer, and on-axis light passes through the switchable ZBD view angle control LCD and the front polarizer. When the switchable ZBD view angle control LCD is in the second state, the view angle control device operates in a wide angle view mode in which the polarization state of the light from the polarized light source is not changed by the switchable ZBD view angle control LCD and passes through the front polarizer.