Driver for a Display Device

1 . A driver for a display device comprising a plurality of pixels; the driver being arranged to drive the display device to display a hologram of a picture on the plurality of pixels such that, when the display device is suitably illuminated, a holographic reconstruction of the picture is formed;

wherein the holographic reconstruction comprises a plurality of image points and the hologram is arranged such that each image point of the holographic reconstruction is formed using a contiguous group of pixels of the display device;

wherein each contiguous group of pixels has a first shape comprising a first side and a second side, wherein the first and second sides are arranged such that, if the first shape is replicated, a respective first side of a first replica of the first shape is suitable for cooperating with a respective second side of a second replica of the first shape.

2 . The driver as claimed in claim 1 , wherein a Fourier transform of the hologram has a second shape corresponding to the first shape.

3 . The driver as claimed in claim 2 , wherein the second shape is such that, if a Fourier transform of the hologram is replicated by a hologram replicator, a respective first side of a first replica of the Fourier transform of the hologram is suitable for co-operating with the respective second side of a second replica of the transform of the hologram.

4 . The driver as claimed in claim 1 , wherein the first shape is a shape that is suitable for providing a packing density of 90% or greater.

5 . The driver as claimed in claim 1 , wherein the first shape is substantially non-circular.

6 . The driver as claimed in claim 1 , wherein the first shape is a shape that is suitable for monohedral tessellation.

7 . The driver as claimed in claim 1 , wherein the first shape is a shape that is suitable for forming a continuous surface when the first shape is replicated in a first direction, the continuous surface comprising replicas of the first shape that fit together and/or abut one another.

8 . The driver as claimed in claim 1 , wherein the first shape comprises a third side and an opposing fourth side, wherein the third side has a shape which corresponds to the fourth side such that the third side is suitable for fitting into/interlocking with the fourth side.

9 . The driver as claimed in claim 1 , wherein the first shape is a quadrilateral shape.

10 . The driver as claimed in claim 1 , wherein the first shape is a rectangle or a square.

11 . The driver as claimed in claim 1 , wherein the hologram is arranged such that a distance between the display device and the holographic reconstruction is 20 millimetre or less.

12 . The driver as claimed in claim 1 , wherein each contiguous group of pixels comprises less than 100,000 pixels.

13 . An optical system having a viewing window, wherein the optical system comprises:

a display device arranged to be driven by a driver as claimed in claim 1 , the display device being further arranged to spatially modulate light in accordance with the hologram displayed thereon to form a holographic wavefront, wherein the holographic wavefront forms the holographic reconstruction downstream of the display device;

a waveguide arranged to receive the holographic wavefront and waveguide the holographic wavefront between a pair of reflective surfaces thereof, wherein one surface of the pair of reflective surfaces is partially transmissive such that a plurality of replicas of the holographic wavefront are emitted therefrom.

14 . The optical system as claimed in claim 13 , wherein the optical system further comprises an optical component between the holographic reconstruction and the waveguide, wherein the optical component is arranged to form a virtual image of the holographic reconstruction upstream of the display device.

15 . The optical system as claimed in claim 14 , wherein:

a distance between the holographic reconstruction and the optical component is less than a focal length of the optical component such that the image of the holographic reconstruction is a virtual image formed upstream of the display device; or

wherein the optical system further comprises an optical relay between the display device and waveguide, the optical relay comprising two lens arranged in cooperation to form a relayed holographic reconstruction, wherein the relayed holographic reconstruction is an image of the holographic reconstruction formed by the hologram displayed on the display device, and wherein a distance between the relayed holographic reconstruction and the optical component is less than a focal length of the optical component such that the virtual image of the holographic reconstruction formed by the optical component is a virtual image of the relayed holographic reconstruction.

16 . The optical system as claimed in claim 13 , wherein the optical component is arranged such that the holographic wavefront coupled into the waveguide is a transform of a holographic wavefront encoding the picture.

17 . A display device comprising a plurality of pixels;

wherein the display device is arranged to display a hologram of a picture on the plurality of pixels such that, when the display device is suitable illuminated, a holographic reconstruction of the picture is formed;

wherein the display device is arranged such that each image point is formed using a contiguous group of pixels of the display device; and

wherein each contiguous group of pixels has a first shape comprising a first side and a second side, wherein the first and second sides are arranged such that, if the first shape is replicated, a respective first side of a first replica of the first shape is suitable for cooperating with a respective second side of a second replica of the first shape.

18 . A method of calculating a hologram of a picture for an optical system comprising a display device arranged to display the hologram, the picture comprising a plurality of image points, the method comprising:

for each image point, defining an area on the display device using straight line paths from the image point to the display device;

determining a sub-hologram for each image point and displaying the sub-hologram on the respective area of the display;

wherein each area on the display device has a first shape comprising a first side and a second side, wherein the first and second sides are arranged such that, if the first shape is replicated, a respective first side of a first replica of the first shape is suitable for cooperating with a respective second side of a second replica of the first shape.

19 . The method as claimed in claim 18 , wherein each area comprises a contiguous group of pixels, and the step of displaying the sub-hologram comprises displaying the sub-hologram on the respective contiguous group of pixels.

20 . The optical system as claimed in claim 16 , wherein the optical component is arranged such that the holographic wavefront coupled into the waveguide is a Fourier transform of the holographic wavefront.