Optical Modules for Micro-LED Displays
40 patents in this list
Updated:
Micro-LED displays face significant optical challenges at the pixel level, where emission angles can exceed 120 degrees and cross-talk between sub-pixels impacts color purity. Current designs achieve only 20-30% extraction efficiency, with substantial light loss occurring at material interfaces and through total internal reflection within the LED structure.
The fundamental challenge lies in maximizing light extraction and directionality while maintaining the ultra-small form factors required for high-resolution displays.
This page brings together solutions from recent research—including integrated micro-lens arrays, reflective cavity designs, wavelength-selective mirrors, and crystalline waveguide structures. These and other approaches focus on practical manufacturing methods while addressing both efficiency and color quality requirements for next-generation displays.
1. Near-Eye Display with Single-Layer Optical Waveguide Featuring Coupling, Relay, and Outcoupling Units for Balanced RGB Diffraction
HUAWEI TECH CO LTD, HUAWEI TECHNOLOGIES CO LTD, 2023
Near-eye display with improved color uniformity and light efficiency using a single-layer optical waveguide. The display has a substrate with coupling, relay, and outcoupling units. The coupling units bring the RGB beams into the waveguide, the relay units diffract them, and the outcoupling unit exits the waveguide. The relay units optimize the diffraction angles of R, G, and B beams to balance light energy and improve color uniformity. The relay and outcoupling units can be on opposite substrate surfaces for simplicity.
2. Optical Waveguide with Reflective Side Walls and Surface In-Coupling and Out-Coupling Areas
APPOTRONICS CORP LTD, APPOTRONICS CORPORATION LTD, 2023
An optical waveguide design for efficient light coupling in augmented reality and display devices. The waveguide has an in-coupling area and an out-coupling area on one surface. The other surface is blank. The side walls have a reflective layer facing inside the waveguide. Light entering through the in-coupling area travels down the waveguide, reflects off the side walls, and exits through the out-coupling area. This prevents light from escaping the waveguide and ensures nearly 100% coupling efficiency. The waveguide can be used with a light source, display panel, and projection lens in AR/VR headsets.
3. Micro-LED Display Pixel Structure with Sub-Pixel Lenses and Reflectors for Light Collimation and Cross-Talk Reduction
Plessey Semiconductors Limited, 2023
Micro-LED display pixels to improve color purity and efficiency by collimating emitted light and reducing cross-talk between sub-pixels. Each pixel has multiple sub-pixels with lenses and reflectors that contain and redirect the emitted light. The reflectors reflect pump light and transmit converted light. They also have apertures to limit cross-talk. This improves efficiency by preventing unconverted pump light from escaping the pixel. The lenses collimate the light to increase collection efficiency. The reflectors and lenses are designed to match and optimize the sub-pixel emissions.
4. Waveguide Structure with Perpendicular Optical Channels and Transflective Elements for Light Confinement and Expanded Viewing Angles
SHIHU TECH NANJING CO LTD, SHIHU TECHNOLOGY CO LTD, 2023
Waveguide structure and display device for high brightness and integrity of displayed images with expanded optical aperture. The waveguide structure has multiple optical channels arranged perpendicularly. Each channel has transflective parts to guide light. Barriers between channels prevent light crosstalk. This constrains light propagation in multiple dimensions. Stacked waveguide structures with different viewing angles expand the viewable field. This allows using a single waveguide structure group to display the entire field of view from an image source.
5. Circular Arc MicroLED Arrangement with Common Emission Angle Alignment
Xiamen Extremely PQ Display Technology Co., Ltd., 2023
MicroLED pixel configuration and display panel design to avoid dispersion and color inconsistency problems in small angle microLED displays. Multiple microLEDs of different colors are arranged on a circular arc with a common center point. The microLEDs emit light towards an optical component that collects and emits the light at a preset angle. The microLEDs are positioned so their light beams coincide after rotating around the center point. This ensures the emitted light from all microLEDs enters and exits the optical component at the same angle, preventing dispersion and color variation when using optical components to narrow the viewing angle.
6. Waveguide-Based Near-Eye Display System with Integrated Optical Elements for Beam Shaping
GOOGLE LLC, 2023
Compact near-eye display system with integrated optics in a waveguide to reduce size and complexity compared to conventional display systems. The display uses a waveguide with an input coupler to receive display light from an optical engine. Inside the waveguide, integrated optical elements apply optical functions like collimation or focusing to the display light before output. This allows compact integration of functions like beam shaping without needing separate components like beam splitters and mirrors. The waveguide can have a green peak response for better image perception.
7. Waveguide Array Illuminator with Inline Outcouplers and Variable Geometry for Uniform Sub-Beam Extraction
META PLATFORMS TECHNOLOGIES LLC, 2023
Waveguide-based illuminator for high efficiency display panels. The illuminator has a waveguide array with parallel waveguides. Sub-beams are split from an input beam and guided through the array. Inline outcouplers extract sub-beams from each waveguide to form a 2D array. Flattening techniques like varying duty cycle, width, or height with distance from splitter improve uniformity. The outcoupled sub-beams illuminate the display pixels. Multiple waveguide arrays can interleave for opposite propagation directions.
8. Waveguide Display with Micro-Optic Couplers for Wavelength Separation and Collimation
JIANGXI PHOENIX OPTICAL TECHNOLOGY CO LTD, 2023
Waveguide display that avoids color crosstalk by using micro-optics and couplers to separate and collimate the light from different wavelengths to prevent color mixing. The display has separate incident couplers to split the light from each wavelength into views with different angles. The light is then guided through separate waveguide plates and collimated at the output couplers to maintain the separate views without crosstalk. This allows stacking multiple waveguide layers for increased FOV without color mixing.
9. Micro-LED Display Module with Integrated Micro-Lens Array and Quantum Dot Ink-Based Color Conversion Barriers
ANYCASTING CO., LTD., 2022
Micro-LED display module with built-in color conversion function to improve efficiency and simplify manufacturing of micro-LED displays without separate color conversion layers. The display has a micro-lens array above the micro-LEDs. The lenses focus and direct the light while the array's barriers and color converters between the lenses convert the LED colors. This eliminates the need for separate color conversion films. The converters are formed in the barriers using quantum dot ink. The array also has absorber layers to prevent cross-talk and reflection layers to increase efficiency.
10. Waveguide-Based Collimated Illumination Device with Micro-Lenses, Mirrors, and Light Recycling Films
REALD SPARK LLC, 2022
Collimated illumination device for displays, lighting, and AR/VR that provides focused light output from a thin package. The device uses a waveguide with micro-lenses, mirrors, and light recycling films to extract and collimate light from behind the waveguide. This allows high efficiency, uniformity, and brightness in a compact space. The collimated output can be switched between wide and narrow angles for privacy displays, environmental lighting, and AR/VR headsets. The collimation reduces glare and improves visibility compared to wide-angle displays. The collimated light also enables local dimming in high dynamic range displays.
11. Micro LED Structure with Asymmetric Lenses and Reflective Cups for Enhanced Light Directionality
Lextar Electronics Corporation, 2022
Micro LED structure for AR/VR displays with improved light patterns using optical structures like lenses and reflective cups over each micro LED chip. The micro LED structure includes multiple micro LED chips arranged in a line, each with a reflective coating around the sidewalls. Optical structures, such as asymmetric lenses and reflective cups, are placed over each micro LED chip to shape and direct the light output.
12. Backlight Unit with Multi-Directional Triangular Pyramid Lens Sheets and Color Conversion for Mini-LED and Micro-LED Displays
LMS CO., LTD., 2022
Backlight unit for displays that uses mini-LEDs or micro-LEDs as light sources for improved contrast and power efficiency. The backlight has a color conversion sheet to convert the LED light, a first diffusion lens sheet with triangular pyramid lenses aligned in one direction, and a second diffusion lens sheet with triangular pyramid lenses aligned in another direction at an angle to the first. This separates and diffuses the LED light to reduce hot spots and improve uniformity.
13. LED Display Panel with Integrated Micro Lenses and Optical Spacer for Collimated Light Emission
Jade Bird Display (Shanghai) Limited, 2022
LED display panel with integrated micro lenses for improving brightness and reducing crosstalk in LED displays. The panel has an array of pixel driver circuits, an array of LED dies, an array of micro lenses, and an optical spacer between the LED and micro lens arrays. The micro lenses are formed on the LEDs to collimate the light emission and reduce divergence. This improves display brightness, reduces light crosstalk between pixels, and allows using projection lenses with smaller apertures.
14. Micro-LED Array with Offset Micro-Lenses and Backside Reflectors
Facebook Technologies, LLC, 2022
Micro-LEDs with micro-lenses for improving efficiency of micro-LED displays and eye tracking. Micro-LEDs with mesa structures and backside reflectors are paired with micro-lenses. The lenses extract light from the LEDs and direct it in desired directions. This optimizes the beam profiles for efficient coupling into waveguide displays and onto users' eyes. The lenses have offsets from the LED centers that vary across the array. This causes the lens chief rays to propagate at angles that counteract walk-off in the display optics. The LEDs themselves have narrow beam profiles for high extraction efficiency.
15. Micro LED Array with Integrated Waveguide and Reflective Facet Collimation System
REALD INC, 2022
Narrow angle collimated lighting device using micro LEDs and waveguides for applications like displays, headlights, and lighting. The device has an array of micro LEDs emitting light through a transparent substrate. Behind each micro LED is an optical element consisting of a waveguide with reflective facets. The waveguide guides and collimates the light from the micro LED. The reflective facets reflect the collimated light back into the waveguide for extraction through the transparent substrate. This provides collimated output from the micro LEDs without the need for external optics.
16. Crystalline Semiconductor Waveguides for Collimation of Micro Light Emitting Diodes
Facebook Technologies, LLC, 2022
Micro light emitting diodes (μLEDs) used as a light source for displays and other applications suffer from poor collimation of the emitted light due to their small size. Waveguides made of transparent crystalline semiconductor material are used as secondary optics to reduce the beam divergence of μLEDs. The waveguides capture and confine the light from the LED to transmit it with reduced divergence. This allows efficient collimation without using lenses. The waveguides are fabricated from crystalline semiconductor materials like GaN that are transparent to the LED's emission wavelengths.
17. Micro LED Display with Lateral Displacement Micro Lenses for Light Collimation and Extraction
FACEBOOK TECH LLC, FACEBOOK TECHNOLOGIES LLC, 2022
Micro LED displays with micro lenses to improve efficiency and reduce walk-off. The displays have arrays of microscopic LEDs with corresponding micro lenses on top. The lenses extract and collimate the LED light. They have different lateral displacements from the LEDs to direct the principal rays in unique directions. This compensates for the internal LED walk-off effect. The lenses also extract more light compared to direct extraction. The lenses can be fabricated using techniques like photolithography and direct etching.
18. Switchable Micro LED Array Lighting Device with Variable Angle Optical Element Configuration
RAYLEIGH D SPARKER LIMITED RESPONSIBILITY CO, RAYLEIGH D SPARKER LTD RESPONSIBILITY CO, 2022
Switchable lighting device for displays, backlighting, and ambient lighting that can switch between narrow and wide angle illumination. The device uses an array of sub-arrays of micro LEDs behind a transmissive substrate. Each sub-array has an associated optical element with a rear layer, transmissive material, and transmissive substrate matching refractive index. The rear layer reflects light back into the waveguide formed by the layers. Extraction facets guide light out through the substrate. This provides collimated narrow angle light from the micro LEDs. By switching the light input structure, light is guided wider angles through total internal reflection. This allows narrow angle viewing for individual users vs wide angle for groups.
19. Multilayer Optical Film with Bead and Pattern Diffusion Layers and Integrated Prism Sheet
LMS CO., LTD., 2022
Optical film for diffusing and collecting light from mini or micro LEDs that efficiently and uniformly diffuses and collects the light from mini LEDs or micro LEDs. The film includes a first diffusing sheet with a bead diffusion layer on one surface and a pattern diffusion layer on the other surface, and a prism sheet to collect the diffused light. The bead layer difuses light more than the pattern layer to optimize diffusion from mini LEDs.
20. Semiconductor Light Emitting Device with Planar Optical Components Formed by Differential Oxidation and Etching of Multi-Layer Structures
FACEBOOK TECHNOLOGIES, LLC, 2021
Semiconductor light emitting devices like LEDs with planar optical components to more precisely modify the emission pattern using epitaxial growth and lateral oxidation/etching techniques. The components are formed from multiple semiconductor layers with varying compositions that oxidize/etch at different rates. Trenches are formed and the layers oxidized/etched to create optical components like micro-lenses or prisms. The layer thickness and composition are precisely controlled to fabricate the components using standard semiconductor processing. This allows integrated and efficient fabrication of devices with tailored light emission.
Achieving stunning visuals with micro-LED displays requires precise light control, and advancements in micro-LED optical modules are crucial. These modules offer a variety of solutions, like integrated quantum dot technology and optimized pixel designs, to deliver rich and pure colors.
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