US 12,135,526 B2
Holographic projection
Louis Vallet, Milton Keynes (GB); and Michal Wengierow, Milton Keynes (GB)
Assigned to Envisics Ltd, Milton Keynes (GB)
Filed by ENVISICS LTD, Milton Keynes (GB)
Filed on Sep. 30, 2021, as Appl. No. 17/491,099.
Claims priority of application No. 2015652 (GB), filed on Oct. 2, 2020.
Prior Publication US 2022/0107606 A1, Apr. 7, 2022
Int. Cl. G09G 3/20 (2006.01); G03H 1/08 (2006.01); G03H 1/22 (2006.01)
CPC G03H 1/2294 (2013.01) [G03H 1/0866 (2013.01); G03H 1/2205 (2013.01); G09G 3/20 (2013.01); G03H 2001/2297 (2013.01); G03H 2222/12 (2013.01); G03H 2240/51 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of holographic projection, the method comprising:
(i) receiving an image for projection and determining a pixel usage of the image;
(ii) forming an image frame comprising a first image region and second image region, wherein the first image region corresponds to the image and the second image region corresponds to non-image content representative of a system control parameter;
(iii) applying a first gain factor to the non-image content in order to change a grey level of the non-image content of the image frame, wherein the first gain factor is determined based on the pixel usage, and wherein the first gain factor is proportional to the pixel usage;
(iv) calculating a hologram of the image frame;
(v) displaying the hologram and illuminating the hologram with light from a light source to form a holographic reconstruction of the image frame;
(vi) measuring a parameter representative of the luminance of the holographic reconstruction of the non-image content;
(vii) scaling the measured parameter in accordance with an inverse of the first gain factor, to obtain a parameter value that is representative of a true luminance of the holographic reconstruction of the non-image content; and
(viii) controlling the optical power of the light illuminating the hologram until the true luminance of the holographic reconstruction of the non-image content indicates that a target luminance is met, for the holographic reconstruction of the image content of the image frame.