Light Control Device

A head-up display comprising:

• one or more processors arranged to determine a hologram of an image;
• a spatial light modulator configured to display the hologram;
• one or more coherent light sources configured to illuminate the hologram with coherent light, such that the coherent light is spatially modulated to produce a diverging holographic wavefront;
• a waveguide replicator comprising:
• an input surface arranged to receive the diverging holographic wavefront;
• and
• a reflective surface and a transmissive-reflective surface arranged to replicate the diverging holographic wavefront by waveguiding the diverging holographic wavefront between the reflective surface and the transmissive-reflective surface to form a two-dimensional array of replicas of the diverging holographic wavefront,
• wherein the transmissive-reflective surface forms an output surface configured to emit the two-dimensional array of replicas of the diverging holographic wavefront;
• and
• a light control device located in an optical path of the two-dimensional array of replicas of the diverging holographic wavefront downstream from the output surface of the waveguide replicator wherein the light control device is arranged to apply a negative optical power to the two-dimensional array of replicas of the diverging holographic wavefront such that a spacing of the two-dimensional array of replicas of the diverging holographic wavefront at an eye-box is increased by the light control device due to the diverging nature of the light control device caused by its negative optical power.