Auto-stereoscopic display device

A method for driving a multi-view auto-stereoscopic display device, the method comprising acts of:

• forming an imager that includes an array of display pixels for producing a display;
• forming an array of view forming elements positioned over the imager, the view forming elements each being configurable to focus outputs of groups of the display pixels into a plurality of views projected from an output surface of the multi-view auto-stereoscopic display device towards a user in different directions;
• forming deflector positioned over the array of view forming elements, the deflector being arranged to selectably change the directions in which the plurality of views including successive views are projected towards the user resulting in a shift Xshift,view which is a difference between values of Xview for the successive views where a first projected view is next to a second projected view, Xview being a horizontal distance between a center of a display pixel of one of the groups of the display pixels which generates a view and an axis of an associated view forming element of the array of view forming elements;
• driving the imager with display data;
• and
• controlling the deflector to change the directions in which the plurality of views formed by the view forming elements are projected towards the user,
• wherein the deflector comprises at least one birefringent prism having simultaneously a first refractive index for light having a first polarization direction and a second refractive index for light having a second polarization direction, the deflector further comprising a polarization switch and at least one optically isotropic prism, the polarization switch being in registration with the birefringent prism for directly providing the birefringent prism with display light selectably having the first or second polarization direction, the display light passing from the at least one birefringent prism to the at least one optically isotropic prism for direct exit from the output surface towards the user, the at least one optically isotropic prism being more optically isotropic than the at least one birefringent prism,
• wherein the array of view forming elements is arranged between the imager and the deflector, wherein the array of view forming elements comprises an array of lenticular lenses and wherein the imager is arranged adjacent to a convex surface of the lenticular lenses, and the view deflecting deflector is arranged adjacent to a plane surface of the lenticular lenses,
• wherein the view forming elements are configurable to project the plurality of views in directions that are separated by constant angles, and wherein the view deflecting deflector is arranged to selectably change the directions in which the plurality of views are projected by the substantially constant angles, and
• wherein separation angles between consecutive views of the plurality of views projected by the view forming elements are substantially double deflection angles by which the plurality of views are changed by the view deflecting deflector,
• wherein the at least one birefringent prism comprises a first surface for receiving light into the at least one birefringent prism and a second surface for transmitting light out from the at least one birefringent prism, the first surface contacting the second surface to form an acute angle,
• wherein the at least one isotropic prism comprises a third surface and the output surface, the third surface receiving light into the at least one isotropic prism from the second surface, and the output surface being an outer surface of the multi-view auto-stereoscopic display device and transmitting light of the different directions out directly from the at least one isotropic prism towards the user, the third surface contacting the output surface to form the acute angle.

An auto-stereoscopic display device, comprising:

• image forming means having an array of display pixels for producing a display;
• view forming means positioned over and in registration with the image forming means and having an array of view forming elements, the view forming elements each being configurable to focus outputs of groups of the display pixels into a plurality of views projected from an output surface of the auto-stereoscopic display device towards a user in different directions;
• and
• a view deflecting means positioned over and in registration with the view forming means, the view deflecting means being arranged to selectably change the directions in which the plurality of views including successive views are projected towards the user resulting in a shift Xshift,view which is a difference between values of Xview for successive views where a first projected view is next to a second projected view, Xview being a horizontal distance between a center of a display pixel of one of the groups of the display pixels which generates a view and an axis of an associated view forming element of the array of view forming elements, the view deflecting means comprising a polarization switch, at least one birefringent prism and at least one optically isotropic prism, the at least one birefringent prism having simultaneously a first refractive index for light having a first polarization direction and a second refractive index for light having a second polarization direction, the polarization switch directly providing the at least one birefringent prism with display light selectably having the first or second polarization direction, the display light passing from the at least one birefringent prism to the at least one optically isotropic prism for direct exit from the output surface towards the user, the at least one optically isotropic prism being more optically isotropic than the at least one birefringent prism,
• wherein the view forming means are arranged between the image forming means and the view deflecting means,
• wherein the at least one birefringent prism comprises a first surface for receiving light into the at least one birefringent prism and a second surface for transmitting light out from the at least one birefringent prism, the first surface contacting the second surface to form an acute angle,
• wherein the at least one isotropic prism comprises a third surface and the output surface, the third surface receiving light into the at least one isotropic prism from the second surface, and the output surface being an outer surface of the auto-stereoscopic display device and transmitting light of the different directions out directly from the at least one isotropic prism towards the user, the third surface contacting the output surface to form the acute angle.