Holographic projection system

Abstract

A holographic projection system for forming, at a replay plane, a holographic reconstruction of a picture comprising an array of pixels, the system comprising a detector arrangement to detect light received by a first detection area (1205, fig.11); wherein an optical alignment process comprises: selecting a first pixel of the array of pixels; forming a first holographic reconstruction of a first picture, the first picture comprising a control region 1606 (1202, fig.11) comprising the selected first pixel; moving the first holographic reconstruction between a plurality of positions with respect to the first detection area in a first dimension 1604 of the replay plane (scanning / translating the holographic reconstruction with respect to a detector, for example using grating functions); and determining a value for a parameter (e.g power) of the light received by the detection area in each of the plurality of positions; wherein, if the parameter value does not meet a threshold condition over the plurality of positions, the optical alignment process is repeated using a second pixel of the array of pixels that neighbours the first pixel; and a second holographic reconstruction of a second picture is formed, the second picture comprising a control region 1608 comprising the second pixel.

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