Beam shaping device

A switchable autostereoscopic display device comprising:

• a display panel having an array of display pixel elements for producing a display, the array of display pixel elements being arranged in rows and columns;
• and
• an imaging arrangement which directs an output from different pixel elements to different spatial positions to enable a stereoscopic image to be viewed, arranged such that display pixel outputs for both eyes of a viewer are simultaneously directed,
• wherein the imaging arrangement is electrically switchable between a 2D mode and a 3D mode and comprises a beam shaping apparatus comprising:
• top and bottom optically transparent substrates,
• a liquid crystal layer sandwiched between the top and bottom optically transparent substrates,
• a first electrode arranged on one side of the liquid crystal layer facing the top optically transparent substrate configured as a first plurality of conductor lines connected together and extending in a plane parallel to the top optically transparent substrate,
• a second electrode arranged on the one side of the liquid crystal layer facing the top substrate configured as a second plurality of conductor lines connected together and extending in the plane formed by the first plurality of conductor lines such that the second plurality of conductor lines are intertwined in the plane with the first plurality of conductor lines of the first electrode, wherein the beam shaping apparatus is controllable to change between a plurality of beam-shaping states, each permitting passage of a light beam through the beam shaping apparatus in a direction perpendicular thereto, and
• a conductor plate extending across the first and second electrodes, coupled to a voltage source and positioned on an opposite side of the liquid crystal layer to the first and second electrodes, wherein each of the first and second electrodes permitting passage of the light beam through the switchable autostereoscopic display device in a direction perpendicular thereto, and is configured to respond to a voltage across the first and second electrodes together with interaction with the conductor plate resulting in an in-plane electric field extending from ones of the first plurality of conductor lines to neighboring second plurality of conductor lines thereby providing the in-plane electric field that extends essentially parallel to the liquid crystal layer throughout between each of the first and second pluralities of conductor lines including a span directly in line with the first and second pluralities of conductor lines adjacent to the one side of the liquid crystal layer and extending substantially throughout the liquid crystal layer from the first and second plurality of conductor lines on the one side of said liquid crystal layer to the opposite side of the liquid crystal layer.

A beam shaping device comprising:

• top and bottom optically transparent substrates;
• a liquid crystal layer sandwiched between the top and bottom optically transparent substrates;
• and
• first and second electrodes arranged on one side of the liquid crystal layer facing the top optically transparent substrate,
• wherein the beam shaping device is controllable to change between a plurality of beam-shaping states, each permitting passage of light through a beam-shaping device in a direction perpendicular thereto, and is configured to respond to a voltage across the first and second electrodes resulting in an electric field including a portion essentially parallel to the liquid crystal layer in a segment thereof between neighboring portions of the first and second electrodes and extending substantially from the top substrate to the bottom substrate, and
• wherein a distance between neighboring portions of the first and second electrodes is p, a thickness of the liquid crystal layer is dsolid, a permittivity of one of the top and bottom optically transparent substrates in contact with the liquid crystal layer is εsub and a component of a permittivity of liquid crystal material parallel to an extraordinary axis is εLC, and wherein:
• 0.7<a1<12, in which a1=εLC×dsolid/p.