US 11,927,785 B2
Holographic optical element and method of forming thereof
Tze Peng Kevin Lim, Singapore (SG); Kwang Wei Joel Yang, Singapore (SG); and Hailong Liu, Singapore (SG)
Assigned to SINGAPORE UNIVERSITY OF TECHNOLOGY AND DESIGN, Singapore (SG)
Appl. No. 17/047,074
Filed by SINGAPORE UNIVERSITY OF TECHNOLOGY AND DESIGN, Singapore (SG)
PCT Filed Apr. 15, 2019, PCT No. PCT/SG2019/050213
§ 371(c)(1), (2) Date Oct. 13, 2020,
PCT Pub. No. WO2019/199235, PCT Pub. Date Oct. 17, 2019.
Claims priority of application No. 10201803137R (SG), filed on Apr. 13, 2018.
Prior Publication US 2021/0364686 A1, Nov. 25, 2021
Int. Cl. G02B 5/32 (2006.01); G03H 1/00 (2006.01); G03H 1/26 (2006.01); B42D 25/328 (2014.01)
CPC G02B 5/32 (2013.01) [G03H 1/0011 (2013.01); G03H 1/26 (2013.01); B42D 25/328 (2014.10); G03H 2001/261 (2013.01); G03H 2223/15 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A holographic optical element comprising:
a hologram portion comprising a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and
a colour filter portion formed on the hologram portion, the colour filter portion comprising a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion,
wherein the plurality of groups of unit regions of the colour filter portion is spatially arranged to collectively form a predetermined colour image thereon viewable under a white light illumination, and
wherein the light illuminations associated with the plurality of groups of unit regions of the hologram portion, respectively, for producing the respective holographic images are laser illuminations and the respective predetermined wavelengths of the laser illuminations are different from each other.