# US 2019/0170321 A1 · Compact Holographic Illumination Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170321 A1 - Document ID: US20190170321A1 - Status: Published application - Kind: A1 - Application number: 16/208,050 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2005-11-11 - Assignees: DigiLens Inc. - Applicants: DigiLens Inc. - Inventors: Milan Momcilo Popovich; Jonathan David Waldern - Web page: https://patentgrep.com/patent/US20190170321A1 ## CPC - F21V 5/04: of lens shape - F21K 9/64: using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer - G02B 5/32: Holograms used as optical elements - G02B 27/102: {for generating a colour image from monochromatic image signal sources} - G02B 27/1086: {operating by diffraction only} - G02B 27/42: Diffraction optics {, i.e. systems including a diffractive element being designed for providing a diffractive effect}(G02B27/60 takes precedence) - G02F 1/133606: {including a specially adapted diffusing, scattering or light controlling members} - H04N 9/3152: {for shaping the light beam (beam shaping per se G02B27/09)} - H04N 9/3164: {using multiple light sources} - F21Y 2113/13: comprising an assembly of point-like light sources - F21Y 2115/10: Light-emitting diodes [LED] - G02F 1/133607: {the light controlling member including light directing or refracting elements, e.g. prisms or lenses} - G02F 1/133613: {characterized by the sequence of light sources} - G02F 2203/62: Switchable arrangements whereby the element being usually not switchable - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## Abstract There is provided a colour sequential illumination device comprising in series: first and second light sources; a condenser lens; and a grating device. The grating device comprises at least one Bragg grating. The condenser lens directs light from the first and second sources into the grating device at first and second incidence angles respectively. The grating device diffracts light from the first and second sources into a common direction. Desirably, the Bragg gratings are Electrically Switchable Bragg Gratings. In one embodiment of the invention the light sources are Light Emitting Diodes. Alternatively lasers may be used. ## Claims ### Claim 1 An illumination device comprising: at least one light source; a collimating lens; at least one Bragg grating; and a diffractive optical element (DOE), wherein said grating device comprises at least one Bragg grating; a light input port and a light output port, wherein said DOE modifies the wavefront characteristics of said light to control the spatial distribution of the illumination provided by said light at an illumination surface. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said at least one Bragg grating is an electrically switchable Bragg grating. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein said at least one Bragg grating multiplexes gratings for diffracting different colors. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein said DOE modifies said illumination to compensate for at least one selected from the group consisting of source illumination distribution, optical aberration and vignetting. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein said DOE is a computer-generated hologram. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein said at least one Bragg grating and said DOE each have diffusing properties for controlling the spatial distribution of the illumination at said illumination surface. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein said DOE modifies the beam shape of said light. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein said DOE diffracts two or more colors. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein said at least one light source comprises red, green and blue emitters. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein said at least one light source comprises at least two emitters of the same color. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein said at least one light source comprises first and second emitters of the same color pulsed on and off in anti-phase. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein said at least one light source comprise light emitting diodes. or lasers. ### Claim 13 (depends on 1) The apparatus of claim 1, further wherein said at least one light source are disposed on a curved substrate. ### Claim 14 (depends on 1) The apparatus of claim 1, further comprising a beam shaping optical element. ### Claim 15 (depends on 1) The apparatus of claim 1, wherein at least one beam shaping optical element is disposed between said at least one light source and said condenser lens. ### Claim 16 (depends on 1) The apparatus of claim 1, further comprising at least one light guiding element for controlling the light beam geometrical characteristics from said at least one light source. ### Claim 17 (depends on 1) The apparatus of claim 1, further comprising a light control film for blocking stray light. ### Claim 18 (depends on 1) The apparatus of claim 1, further comprising a dichroic beamsplitter. ### Claim 19 (depends on 1) The apparatus of claim 1, wherein said at least one Bragg grating comprises: overlapping first and second Bragg gratings and overlapping third and fourth Bragg gratings, wherein said second and third Bragg gratings sandwich a half wave plate, wherein said first and third Bragg gratings have similar optical prescriptions and said second, and fourth Bragg grating have similar optical prescriptions. ### Claim 20 (depends on 1) The apparatus of claim 1, used to illuminate a microdisplay disposed in proximity to said illumination surface.