Abstract: An illumination apparatus comprises a plurality of LEDs aligned to an array of directional optical elements wherein the LEDs are substantially at the input aperture of respective optical elements. An electrode array is formed on the array of optical elements to provide at least a first electrical connection to the array of LED elements. Advantageously such an arrangement provides low cost and high efficiency from the directional LED array.

Abstract: A birefringent lens structure comprises a birefringent lens array capable of directing light of a given polarisation into a directional distribution, the birefringent lens comprising a solid birefringent material and an isotropic material having an interface having a refractive structure. A switchable liquid crystal layer capable of rotating the polarisation of light passing therethrough is arranged adjacent the first birefringent material. The interface between the birefringent material and the liquid crystal layer has an alignment microstructure providing alignment of the birefringent material and the liquid crystal layer. A pair of electrodes for applying an electric field to switch the liquid crystal are arranged with both the lens array and the switchable liquid crystal layer therebetween and a conductive material is incorporated in the lens array to reduce the voltage drop across the lens array.

Abstract: A directional display apparatus, comprising a spatial light modulator comprising an array of pixels and a lens array in which each respective section of the lens array is capable of directing light from a group of pixels aligned with the respective section into nominal viewing windows, is arranged such that each respective section is also capable of directing light from at least one adjacent group of pixels aligned with a section adjacent the respective section into the same nominal viewing windows. This may be achieved by a deflection element, such as a prism element or a hologram, or by each respective section of the lens array having at least one lens surface providing: at least one first region capable of directing light from said group of pixels aligned with the respective section into said nominal viewing windows; and at least one second region capable of directing light from said at least one adjacent group of pixels into the same nominal viewing windows.

Abstract: A display apparatus comprises a spatial light modulator and optical elements in series therewith. The optical elements provide a first parallax element being a parallax barrier capable of directing light output from the display apparatus into a first plurality of viewing windows, and a second parallax element capable of directing light output from the display apparatus into a second plurality of viewing windows. In a first mode, the first and second parallax elements have substantially no directional effect on the light output from the display apparatus. In a second mode, the first parallax element directs light output from the display apparatus into the first plurality of viewing windows and the second optical element has substantially no directional effect. In a third mode, the second optical element directs light output from the display apparatus into the second plurality of viewing windows and the first parallax element has substantially no directional effect.

Abstract: An autostereoscopic display apparatus comprises a spatial light modulator comprising an array of pixels arranged in rows and columns in a pixel plane, and a spatially multiplexing parallax element capable of directing light from successive columns of pixels towards successive ones of two or more viewing windows in a nominal window plane. The pixels comprise pixel apertures having gaps therebetween with the gaps between the columns of pixels extending substantially parallel to the columns of pixels. The arrangement of the pixels is designed taking account of the intensity profile of an image of a nominal human pupil in the nominal window plane formed in the pixel plane by the spatially multiplexing parallax element to reduce the amount of spatially derived flicker observed by a viewer moving in the window plane. In one arrangement, the pixel apertures repeat at a pitch equal to a representative width of said intensity profile.

Abstract: To align a display substrate comprising an array of pixels with a component substrate comprising an array of optical components, the display substrate is divided from a display motherglass formed with an array of panels each comprising an array of pixels sufficient for a single display substrate and with, in respect of each panel, a first alignment feature having a surface relief aligned with the array of pixels. The component substrate is formed with an array of optical components and a second alignment feature aligned with the array of optical components, the second alignment feature having a surface relief shaped to register with the first alignment feature. The display substrates is attached to the component substrate with the first and second alignment features in registration with each other. The alignment of the first alignment feature with the array of pixels may be carried out at the motherglass stage in respect of the entire motherglass.

Abstract: A lens array structure comprises two birefringent lens arrays arranged in series, both being capable of operating to direct incident light of one polarisation into a respective directional distribution and to have substantially no effect on incident light of a polarisation perpendicular to said one polarisation. The lens arrays are relatively oriented such that incident light of two perpendicular polarisation components are directed into a directional distribution by a respective one of the birefringent lens arrays and not affected by other one of the birefringent lens arrays. Thus control of the polarisation allows switching between the effects of the two lens arrays. To allow switching into a third mode in which neither of the lens arrays has effect, one of the lens arrays may be active. The lens structure may be employed in a display apparatus to provide a switchable directional display.

Abstract: A display apparatus has a switchable birefringent lens array. The display apparatus produces a substantially linearly polarised output. The lens array comprises birefringent material arranged between a planar surface of a first substrate and a relief substrate of a second substrate defining an array of cylindrical lenses. The lens array has electrodes for applying a control voltage across the birefringent material for electrically switching the birefringent material between a first mode and a second mode. In the first mode the lens array modifies the directional distribution of incident light polarised in a predetermined direction. In the second mode the lens array has substantially no effect on incident light polarised in said predetermined direction.

Abstract: Control methods and apparatus for controlling driving of switchable display devices are described. The switchable display devices may be switchable between a 2D display mode and a 3D autostereoscopic display mode. Control apparatus (1455) comprising a display mode module (1465), an image data module (1470), an authorisation module (1475), a controller (1480) and a driver module (1485) is described.