# US 2021/0341879 A1 · 2D/3D Holographic Display System > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0341879 A1 - Document ID: US20210341879A1 - Status: Published application - Kind: A1 - Application number: 17/176,355 - Filed: 2021-02-16 - Published: 2021-11-04 - Earliest claimed: 2010-07-14 - Assignees: Dualitas Ltd - Applicants: Dualitas Ltd - Inventors: Jamieson Christmas; Dackson Masiyano - Web page: https://patentgrep.com/patent/US20210341879A1 ## CPC - G02B 27/0103: {comprising holographic elements} - G02B 30/26: of the autostereoscopic type - G03H 1/08: Synthesising holograms, {i.e. holograms synthesized from objects or objects from holograms}(using electric digital computers G06F; G06T) - G03H 1/0891: {Processes or apparatus adapted to convert digital holographic data into a hologram (G03H1/2294 takes precedence)} - G03H 1/2205: {using downstream optical component} - G03H 1/2249: {Holobject properties} - G03H 1/2294: {Addressing the hologram to an active spatial light modulator} - G03H 1/26: Processes or apparatus specially adapted to produce multiple {sub-} holograms or to obtain images from them, e.g. multicolour technique - G02B 2027/0127: {comprising devices increasing the depth of field} - G03H 1/0808: {Methods of numerical synthesis, e.g. coherent ray tracing [CRT], diffraction specific} - G03H 2001/085: {Kinoform, i.e. phase only encoding wherein the computed field is processed into a distribution of phase differences} - G03H 2001/2255: {Holobject out of Fourier or hologram planes} - G03H 2001/2297: {using frame sequential, e.g. for reducing speckle noise} - G03H 2210/20: 2D object - G03H 2210/30: 3D object - G03H 2210/33: 3D/2D, i.e. the object is formed of stratified 2D planes, e.g. tomographic data - G03H 2210/454: into planes - G03H 2225/22: Electrically addressed SLM [EA-SLM] - G03H 2225/32: Phase only - G03H 2225/52: Reflective modulator - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03H: HOLOGRAPHIC PROCESSES OR APPARATUS (holograms, e.g. point holograms, used as ordinary optical elements G02B5/32; producing stereoscopic or other three-dimensional effects G02B30/00; diffraction-grating systems G02B27/44; systems using moiré fringes G02B27/60; optical logic elements G02F3/00; stereo-photography G03B35/00; photosensitive materials or processes for photographic purposes G03C; {stereo-photographic or similar processes G03C9/00}; apparatus for processing exposed photographic materials G03D; analogue computers performing mathematical operations with the aid of optical elements G06E3/00; authentication by radiation, of concealed information carried by holograms or diffraction gratings G06K19/16; holographic storage G11B7/0065, G11C13/04; {stereoscopic or other three dimensional effects in television systems H04N13/00}) ## Abstract A display system (300) comprising an optical system and a processing system. The optical system comprising a spatial light modulator (380), a light source, a Fourier transform lens, a viewing system (320, 330) and a processing system. The spatial light modulator is arranged to display holographic data in the Fourier domain, illuminated by the light source. The Fourier transform lens is arranged to produce a 2D holographic reconstruction in the spatial domain (310) corresponding to the holographic data. The viewing system is arranged to produce a virtual image (350) of the 2D holographic reconstruction. The processing system is arranged to combine the Fourier domain data representative of a 2D image with Fourier domain data representative of a phase only lens to produce first holographic data, and provide the first holographic data to the optical system to produce a virtual image. ## Claims ### Claim 1 A method for displaying a virtual image to a viewer, the method comprising: displaying first holographic data representative of a first two-dimensional (2D) image and first holographic lensing data representative of a first optical power on a phase-modulating spatial light modulator; producing, as a real image in space spatially remote from the viewer, a first 2D holographic reconstruction image, by modulating light from a light source with the spatial light modulator; performing a holographic transform on the light by way of a holographic transform lens; and displaying a first virtual image of the first 2D holographic reconstruction image using an optical viewing system. ### Claim 2 (depends on 1) The method of claim 1, wherein producing the first 2D holographic reconstruction image includes illuminating the spatial light modulator with the light to produce first spatially modulated light, then performing a holographic transform of the first modulated light. ### Claim 3 (depends on 2) The method of claim 2, further comprising, after performing the holographic transform, spatially filtering the light to selectively block at least one diffraction order of the first 2D holographic reconstruction image. ### Claim 4 (depends on 1) The method of claim 1, further comprising: after displaying the first holographic data representative of the first 2D image and the first holographic lensing data on the phase-modulating spatial light modulator, displaying second holographic data representative of a second 2D image and second holographic lensing data representative of a spatial light modulator; producing, as a real image in space spatially remote form the viewer, a second 2D holographic reconstruction image of the second 2D image by modulating the light with the spatial light modulator and performing a holographic transform on the light; and displaying a second virtual image of second 2D holographic reconstruction image using the optical viewing system, wherein the first virtual image and second virtual images are spatially displaced relative to each other to form replay fields at different distances from a viewer. ### Claim 5 (depends on 4) The method of claim 4, wherein producing the second 2D holographic reconstruction image includes illuminating the spatial light modulator with the light to produce second spatially modulated light, then performing a holographic transform of the second modulated light. ### Claim 6 (depends on 5) The method of claim 5, further comprising, after performing the holographic transform, spatially filtering the light to selectively block at least one diffraction order of the first 2D holographic reconstruction image. ### Claim 7 (depends on 1) The method of claim 1, wherein the optical viewing system comprises an imaging lens having a focal length, the lens being disposed at a distance less than the focal length from the position of the real image in space, and wherein the displaying the first virtual image of the first 2D holographic reconstruction image comprises imaging the real image with the imaging lens. ### Claim 8 (depends on 1) The method of claim 1, wherein the first virtual image of the first 2D holographic reconstruction image is displayed on a heads-up display. ### Claim 9 (depends on 1) The method of claim 1, wherein the replay fields are spatially remote from the viewer. ### Claim 10 (depends on 1) The method of claim 1, further comprising selectively blocking at least one diffraction order of the first 2D holographic reconstruction image. ### Claim 11 (depends on 1) The method of claim 1, further comprising selectively blocking a zeroth undiffracted order of the first 2D holographic reconstruction image. ### Claim 12 (depends on 1) The method of claim 1, wherein the spatial light modulator comprises an array of pixelated diffractive elements. ### Claim 13 (depends on 12) The method of claim 12, wherein the spatial light modulator is a phase-only spatial light modulator. ### Claim 14 (depends on 1) The method of claim 1, wherein the first lensing data is representative of a negative optical power. ### Claim 15 (depends on 1) The method according to claim 1, wherein the first holographic data representative of the first 2D image is Fourier-domain data representative of the first 2D image, the first holographic lensing data representative of the first optical power is Fourier-domain lensing data representative of the first optical power, and the holographic transform is a Fourier transform. ### Claim 16 (depends on 1) The method of claim 1, wherein the holographic transform is performed by the first holographic-domain lensing data displayed on the phase-modulating spatial light modulator. ### Claim 17 A display system for displaying a virtual image of a first two-dimensional (2D) image to a viewer, the display system comprising: a holography system configured to produce a first 2D holographic reconstruction image of the first 2D image, the holography system comprising: a processing system configured to provide first holographic data representative of the first 2D image and to provide first holographic lensing data representative of a first optical power; a phase-modulating spatial light modulator configured to receive and display the first holographic data representative of the first 2D image and the holographic lensing data; a light source configured to illuminate the spatial light modulator, the holography system being configured to modulate the light with the spatial light modulator; and a holographic transform lens configured to perform a holographic transform of the modulated light to produce the first 2D holographic reconstruction image; and an optical viewing system configured to displaying a first virtual of the first 2D holographic reconstruction image to the viewer. ### Claim 18 (depends on 17) The display system of claim 17, wherein the light source is configured to illuminate the spatial light modulator to produce a first spatially modulated light. ### Claim 19 (depends on 17) The display system of claim 17, wherein the optical viewing system further comprises a spatial filter configured to selectively block at least one diffraction order of the first 2D holographic reconstruction image. ### Claim 20 (depends on 17) The display system of claim 17, wherein the optical viewing system comprises an imaging lens having a focal length, the lens being disposed at a distance less than the focal length from the position of the real image in space, and wherein the imaging lens is configured to image the real image to form the virtual image. ### Claim 21 (depends on 17) The display system of claim 17, wherein the first phase only lens has a negative optical power. ### Claim 22 (depends on 17) The display system of claim 17, wherein the spatial light modulator is a phase-only spatial light modulator. ### Claim 23 (depends on 17) The display system of claim 17, wherein the processing system is further configured to provide second holographic data representative of a second 2D image and to provide second holographic lensing data representative of second optical power to the first optical power; the phase-modulating spatial light modulator is further configured to, after receiving and displaying the first holographic data representative of the first 2D image and the first holographic lensing data, receive and display the second holographic data representative of the second 2D image and the second holographic lensing data; and the optical viewing system is further configured to, after displaying the first virtual image of the first 2D holographic reconstruction, display a second virtual image of the second 2D holographic reconstruction image to the viewer, the first virtual image and the second virtual image being displayed at different virtual distances from the viewer. ### Claim 24 (depends on 23) The display system of claim 23, wherein the first virtual image and second virtual image are sequential frames of a 2D video stream, but appear to a viewer to be simultaneously present. ### Claim 25 (depends on 17) The display system of claim 17, wherein the first holographic data representative of the first 2D image is Fourier-domain data representative of the first 2D image, the first holographic lensing data representative of the first optical power is Fourier-domain lensing data representative of the first optical power; and the holographic transform is a Fourier transform. ### Claim 26 (depends on 17) The display system of claim 17, wherein the first holographic data representative of the first 2D image is Fourier-domain data representative of the first 2D image, and the holographic transform is a Fourier transform. ### Claim 27 (depends on 17) The display system of claim 17, wherein the first holographic lensing data representative of the first optical power is Fourier-domain lensing data representative of the first optical power; and the holographic transform is a Fourier transform. ### Claim 28 (depends on 17) The display system of claim 17, wherein the system is configured to perform the holographic transform on the light using the first holographic-domain lensing data displayed on the phase-modulating spatial light modulator. ### Claim 29 (depends on 17) The display system of claim 17, configured as a head-up display.