# US 12,002,789 B2 · Display apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,789 B2 - Document ID: US12002789B2 - Status: Granted - Kind: B2 - Application number: 16/760,144 - Filed: 2018-11-05 - Published: 2020-08-13 - Granted: 2024-06-04 - Earliest claimed: 2017-11-05 - Assignees: Optovate Limited - Applicants: Optovate Limited - Inventors: Jonathan Harrold; Graham J. Woodgate - Web page: https://patentgrep.com/patent/US12002789B2 ## CPC - H10W 90/00: Package configurations - G02B 3/0056: {arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085)} - G02B 5/003: {Light absorbing elements} - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B 5/22: Absorbing filters {(G02B5/201 - G02B5/208 take precedence)} - G02B 7/003: {Alignment of optical elements (G02B7/001, G02B7/002 take precedence; for mirrors G02B7/1822)} - G02B 17/08: Catadioptric systems {(used in non-imaging applications G02B19/00)} - G02B 19/0028: {refractive and reflective surfaces, e.g. non-imaging catadioptric systems} - G02B 19/0061: {the light source comprising a LED} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - G09F 9/33: being semiconductor devices, e.g. diodes - H04R 1/028: {associated with devices performing functions other than acoustics, e.g. electric candles} - H10H 20/855: Optical field-shaping means, e.g. lenses - G02B 2003/0093: {characterised by the shape} - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - H04R 2499/15: Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops - H10H 20/84: Coatings, e.g. passivation layers or antireflective coatings - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A display apparatus comprises an array of micro-LEDs and an aligned array of catadioptric optical elements wherein the array of micro optics is further aligned to an array of apertures of a low reflection screen. Advantageously such an arrangement provides a display with large images of configurable size, low cost and high brightness that can achieve high contrast in high illuminance from ambient lighting while also achieving high luminous efficiency. ## Claims ### Claim 1 A display apparatus, comprising: at least one image pixel array relay structure comprising: a plurality of micro-LEDs arranged to output light, the plurality of micro-LEDs being arranged in a micro-LED array; and a plurality of catadioptric optical elements arranged in a catadioptric optical element array, wherein each of the catadioptric optical elements of the plurality of catadioptric optical elements is aligned in correspondence with a respective one or more of the micro-LEDs of the plurality of micro-LEDs, each of the micro-LEDs of the plurality of micro-LEDs being aligned with only a respective one of the catadioptric optical elements of the plurality of catadioptric optical elements; and a low reflection screen comprising a light absorbing structure arranged on a side of a transparent support substrate wherein the light absorbing structure comprises a plurality of light transmitting apertures arranged in an aperture array, the transparent support substrate being arranged between the image pixel array relay structure and the light absorbing structure; wherein the at least one image pixel array relay structure and the low reflection screen are aligned such that the light from each of the micro-LEDs and its respective aligned catadioptric optical element is converged towards and relayed to at least one of the light transmitting apertures by the at least one image pixel array relay structure. ### Claim 2 (depends on 1) A display apparatus according to claim 1 further comprising a control system arranged to provide the plurality of micro-LEDs with image data. ### Claim 3 (depends on 1) A display apparatus according to claim 1 further comprising at least one alignment structure arranged to align the plurality of catadioptric optical elements with the plurality of light transmitting apertures. ### Claim 4 (depends on 3) A display apparatus according to claim 3 wherein the alignment structure further comprises a structure support member arranged to provide mechanical fixing between the image pixel array relay structure and the low reflection screen. ### Claim 5 (depends on 1) A display apparatus according to claim 1 wherein the plurality of micro-LEDs is arranged on a backplane substrate and the plurality of catadioptric optical elements is arranged on an optical substrate. ### Claim 6 (depends on 5) A display apparatus according to claim 5 comprising at least two image pixel array relay structures wherein the image pixel array relay structures are tiled and the low reflection screen is aligned to the at least two image pixel array relay structures. ### Claim 7 (depends on 1) A display apparatus according to claim 1 further comprising a diffuser arranged between the light transmitting aperture regions and the transparent support substrate. ### Claim 8 (depends on 1) A display apparatus according to claim 1 wherein a plurality of lenses is arranged between the catadioptric optical element array and the transparent support substrate. ### Claim 9 (depends on 8) A display apparatus according to claim 8, wherein the plurality of micro-LEDs is arranged on a backplane substrate and the plurality of catadioptric optical elements is arranged on an optical substrate, and wherein the plurality of lenses is arranged on at least one of the optical substrate and the transparent support substrate. ### Claim 10 (depends on 8) A display apparatus according to claim 8 wherein each of the plurality of lenses is arranged to receive light from at least two micro-LEDs of the plurality of micro-LEDs. ### Claim 11 (depends on 1) A display apparatus according to claim 1 wherein the average reflectance to white light of the light absorbing structure is less than 4%, preferably less than 2% and most preferably less than 1%. ### Claim 12 (depends on 1) A display apparatus according to claim 1 wherein the light absorbing structure comprises a microstructured surface. ### Claim 13 (depends on 12) A display apparatus according to claim 12 wherein the microstructured surface comprises a corner cube retro-absorber structure. ### Claim 14 (depends on 12) A display apparatus according to claim 12 wherein the microstructured surface comprises a comb structure. ### Claim 15 (depends on 1) A display apparatus according to claim 1 wherein the low reflection screen is further provided with acoustic apertures. ### Claim 16 (depends on 15) A display apparatus according to claim 15 wherein the acoustic apertures comprise an array of holes to transmit sound. ### Claim 17 (depends on 16) A display apparatus according to claim 16 wherein the array of holes has a profile arranged to reduce light transmission from the image pixel array relay structure. ### Claim 18 (depends on 1) A display apparatus according to claim 1 wherein acoustic transducers are provided on the at least one image pixel array relay structure. ### Claim 19 (depends on 18) A display apparatus according to claim 18 wherein the plurality of micro-LEDs provides blue light and at least one wavelength conversion layer is arranged to convert blue light into yellow or green or red light. ### Claim 20 (depends on 1) A display apparatus according to claim 1 wherein a wavelength conversion layer and/or colour filter is arranged between at least one light transmitting aperture region and the transparent support substrate. ### Claim 21 (depends on 20) A display apparatus according to claim 20 wherein the plurality of micro-LEDs provide white light and red, green and blue colour filters are provided respectively in different light transmitting aperture regions. ### Claim 22 (depends on 1) A display apparatus according to claim 1 wherein a width or diameter of the micro-LEDs is less than 300 microns, preferably less than 200 microns and more preferably less than 100 microns. ### Claim 23 (depends on 1) A display apparatus according to claim 1 wherein in the at least one catadioptric cross-sectional plane some of the light output of micro-LEDs of the plurality of micro-LEDs is transmitted by the at least one transparent inner surface before it is reflected at the first or second outer surfaces and directed into a first directional light output distribution; and some of the light output of the micro-LEDs of the plurality of micro-LEDs is transmitted by the at least one transparent inner surface and directed into the first directional light output distribution without reflection at the first or second outer surfaces. ### Claim 24 (depends on 1) A display apparatus according to claim 1 wherein the plurality of micro-LEDs comprises inorganic micro-LEDs. ### Claim 25 (depends on 1) A display apparatus according to claim 1 wherein the micro-LEDs of the plurality of micro-LEDs are from a monolithic wafer arranged in an array with their original monolithic wafer positions and orientations relative to each other preserved; and wherein in at least one direction, for at least one pair of the plurality of micro-LEDs in the at least one direction, for each respective pair there was at least one respective micro-LED in the monolithic wafer that was positioned in the monolithic wafer between the pair of micro-LEDs in the at least one direction and that is not positioned between them in the array of micro-LEDs. ### Claim 26 (depends on 1) A display apparatus according to claim 1 wherein the second end of at least one catadioptric optical element of the plurality of catadioptric optical elements is arranged on the first side of an optical element support substrate. ### Claim 27 (depends on 1) A display apparatus according to claim 1 wherein the catadioptric optical elements of the plurality of catadioptric optical elements comprise a material transparent to at least one operating wavelength of at least one element of the plurality of micro-LEDs. ### Claim 28 (depends on 1) A composite display apparatus comprising at least two display apparatuses of claim 1 provided in a tiled arrangement. ### Claim 29 (depends on 1) A display apparatus according to claim 1, wherein each of the catadioptric optical elements of the plurality of catadioptric optical elements comprises, in at least one cross-sectional plane through its optical axis: a first outer surface and a second outer surface facing the first outer surface; wherein the first and second outer surfaces extend from a first end of the catadioptric optical element to a second end of the catadioptric optical element, the second end of the catadioptric optical element facing the first end of the catadioptric optical element; wherein the distance between the first and second outer surfaces at the first end of the catadioptric optical element is less than the distance between the first and second outer surfaces at the second end of the catadioptric optical element; and at least one transparent inner surface arranged between the first and second ends and between the first and second outer surfaces. ### Claim 30 (depends on 29) A display apparatus according to claim 29 wherein the alignment in correspondence between a catadioptric optical element of the plurality of catadioptric optical elements and its respective one or more of the micro-LEDs of the plurality of micro-LEDs comprising the respective one or more of the micro-LEDs of the plurality of micro-LEDs being positioned at the first end of the catadioptric optical element and aligned with the catadioptric optical element or positioned between the first end of the catadioptric optical element and the at least one transparent inner surface of the catadioptric optical element and aligned with the catadioptric optical element. ### Claim 31 (depends on 29) A display apparatus according to claim 29 wherein in the at least one catadioptric cross-sectional plane the distance between the first and second outer surfaces at the second end of the catadioptric optical element is less than 3 mm, preferably less than 1.5 mm and more preferably less than 0.75 mm. ### Claim 32 (depends on 29) A display apparatus according to claim 29 wherein the cross-section from one side to another side of the micro-LED is aligned within the first end of the catadioptric optical element. ### Claim 33 (depends on 29) A display apparatus according to claim 29 wherein in the at least one catadioptric cross-sectional plane, an exterior angle between the first end and the first and second outer surfaces at the first end is less than an exterior angle between the first end and the first and second outer surface at the second end. ### Claim 34 (depends on 29) A display apparatus according to claim 29 wherein in the at least one catadioptric cross-sectional plane at least one of the transparent inner surfaces has positive optical power. ### Claim 35 (depends on 29) A display apparatus according to claim 29 wherein in the at least one catadioptric cross-sectional plane at least one of the transparent inner surfaces has zero optical power. ### Claim 36 (depends on 29) A display apparatus according to claim 29 wherein the cross-section from one side to another side of the micro-LED is aligned within the first end of the catadioptric optical element. ### Claim 37 (depends on 29) A display apparatus according to claim 29 wherein a refractive optical element is provided between the micro-LEDs of the plurality of micro-LEDs and the at least one transparent inner surface. ### Claim 38 (depends on 37) A display apparatus according to claim 37 wherein the refractive optical element is a hemispherical lens. ### Claim 39 (depends on 1) A display apparatus according to claim 1 wherein the plurality of micro-LEDs further comprises a wavelength converting layer. ### Claim 40 (depends on 39) A display apparatus according to claim 39 wherein the wavelength converting layer comprises a phosphor material or a quantum dot material.