Multi-view display device
A multi-view display is switchable between single view and multi-view modes, and uses lenticular means ( 9 ) arranged over the display panel which comprise birefringent electro-optic material ( 62 ) adjacent a non-switchable optically transparent layer ( 60 ). The non-switchable optically transparent layer ( 60 ) has a refractive index (n) substantially equal to the extra ordinary refractive index of the birefringent electro-optic material ( 62 ). In the single view mode, the birefringent electro-optic material ( 62 ) defines a non-switched state, and the polarization ( 64 ) of the light output from the display panel and incident on the lenticular means is linear and aligned with the optical axis of the birefringent electro-optic material ( 62 ) at the surface where the display output light is received. In the multi-view mode, the birefringent electro-optic material ( 62 ) defines a switched state in which the optical axis is aligned perpendicularly to the display output surface.
1. A method of controlling a switchable display device, the method comprising:
providing a display panel, and a non-switchable optically transparent layer; and
providing a birefringent electro-optic material disposed between the display and the non-switchable optically transparent layer,
wherein the non-switchable layer comprises a flat side and a lens side,
wherein the flat side is farther from the display panel than the lens side,
wherein the lens side comprises a plurality of lenticular lens elements,
wherein each lens element is convex,
wherein the non-switchable optically transparent layer is disposed over the display panel,
wherein the non-switchable optically transparent layer has a refractive index substantially equal to the extra ordinary refractive index of the birefringent electro-optic material,
wherein a polarization direction of light from the display output side of the display panel and incident on the non-switchable optically transparent layer is linear,
in the single view mode, placing the birefringent electro-optic material in a first state in which an optical axis of the birefringent electro-optic material is aligned with the polarization direction of the light from the display panel at a surface where the light enters the birefringent electro optic material; and
in the multi-view mode, placing the birefringent electro-optic material in a second state in which the optical axis of the birefringent electro-optic material is aligned perpendicularly to a surface of the display panel.
2. The method according to claim 1 , wherein the refractive index of the birefringent electro-optic material is switched between the first state and the second state by a selective application of an electric field to at least part of the birefringent electro-optic material.
3. The method according to claim 1 , wherein in the single view mode the optical axis of the birefringent electro-optic material at a surface of the non-switchable optically transparent layer is aligned with elongate axes of the lenticular lens elements.
4. The method according to claim 1 , wherein the birefringent electro-optic material comprises a twisted nematic liquid crystal material.
5. The method according to claim 1 , wherein the display panel comprises a liquid crystal display panel.
6. The method as claimed in claim 1 , wherein the non-switchable optically transparent layer comprises a birefringent material.
7. The method as claimed in claim 1 , wherein the non-switchable optically transparent layer comprises an isotropic material.
8. The method as claimed in claim 1 , wherein the polarization orientation of the light from the display output side of the display panel at the surface that enters the birefringent electro-optic material is parallel to the elongate axis of the lenticular lens elements.
9. The method as claimed in claim 1 , further comprising a polarizer between the display output side and the non-switchable optically transparent layer.
10. The method as claimed in claim 1 comprising an autostereoscopic display device, wherein the single view mode comprises a two-dimensional mode, and the multi-view mode comprises a three-dimensional mode.
11. The method as claimed in claim 1 comprising a dual view display device, wherein the single view mode comprises a two-dimensional mode in a full field of view of the display, and the multi-view mode comprises two at least partly separated two-dimensional modes at different parts of the full field of view of the display.
12. The method as claimed in claim 1 , wherein the polarization orientation of the light from the display output side of the display panel at the surface that enters the birefringent electro-optic material is in a display column direction.
13. The method as claimed in claim 1 , wherein the polarization orientation of the light from the display output side of the display panel at the surface that enters the birefringent electro-optic material is in a display row direction.
14. The method as claimed in claim 1 , wherein the polarization orientation of the light from the display output side of the display panel at the surface that enters the birefringent electro-optic material is at 45 degrees to the display row and column directions.
15. A method of controlling a switchable display device, the method comprising:
providing a display panel, and a non-switchable optically transparent layer; and
providing a birefringent electro-optic material disposed between the display and the non-switchable optically transparent layer,
wherein the non-switchable layer comprises a flat side and a lens side,
wherein the flat side is farther from the display panel than the lens side,
wherein the lens side comprises a plurality of lenticular lens elements,
wherein each lens element is convex,
wherein the non-switchable optically transparent layer has a refractive index substantially equal to the extra ordinary refractive index of the birefringent electro-optic material,
wherein a polarization direction of light from the display output side of the display panel and incident on the non-switchable optically transparent layer is linear,
in the single view mode, placing the birefringent electro-optic material in a first state in which an optical axis of the birefringent electro-optic material is aligned with the polarization direction of the light from the display panel at a surface where the light enters the birefringent electro optic material; and
in the multi-view mode, placing the birefringent electro-optic material in a second state in which the optical axis of the birefringent electro-optic material is aligned perpendicularly to a surface of the display panel.