Optimizing Color Accuracy in Micro-LED Displays

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.

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This method improves dynamic range, power consumption, and color and gamma correction of micro-LED displays. It involves providing individual emission control signals to each subpixel of each pixel to control emission time and duty cycle independently. This allows tuning color without affecting gamma.

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Full-color LED display using micro-nanofin LED elements that emit the same color for each subpixel. The display has subpixels with two or more vertically stacked micro-nanofin LED elements that emit the same color. The micro-nanofin LED shape increases the emission area compared to rod-shaped micro-LEDs. The micro-nanofin LEDs self-align on the subpixel electrodes when assembled. This allows high-resolution displays without individual LED placement. Micro-nanofin LEDs have higher efficiency and yield than nanorods.

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Micro-LED display system and method to improve dynamic range, power consumption, color accuracy, and gamma correction. The method involves independently controlling each sub-pixel's emission times and duty cycles in a pixel using individualized control signals. This allows precise color adjustment without affecting gamma. It also enables optimizations like varying emission times/duty cycles by grayscale range to reduce power.

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Driving circuits for micro-LED displays that improve color depth and uniformity, reduce power consumption, and improve manufacturability and testability. The circuits separate the digital drive circuits for controlling individual micro-LEDs from the analog drive circuits providing the drive currents. The digital circuits are on a silicon wafer, and the analog circuits are on an indium-gallium-zinc-oxide (IGZO) layer. This allows for optimizing digital and analog circuits using different process technologies.

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A light source apparatus with multiple emitters that can switch between different operating modes to produce tailored color gamuts, such as eye-safe night mode and wide gamut mode. The apparatus contains emitters like blue, cyan, yellow, green, and red that can be selected individually or combined. The emitters are coupled with color-conversion materials tuned to each mode. This allows the device to switch between blue-containing modes for a wide gamut and blue-free modes for eye safety. The multiple modes are supported by adjusting color channel intensities and using optimized conversion materials.

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Method for transferring micro-LEDs from a transfer substrate to a target substrate to enable high-yield manufacturing of displays with uniform brightness and color quality. The transfer method involves sequentially transferring micro-LED subsets in block units from the transfer substrate to the target substrate. In the sequential transfers, the subsets of micro-LEDs transferred to different regions are oriented in the same electrode direction as the first subset to avoid mixing incompatible orientations. This ensures all the transferred micro-LEDs have the same electrode orientation on the target substrate, preventing performance variations at transfer boundaries.

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Micro-LED display panel technology to prevent color mixing caused by light leakage between adjacent micro-LED strips. The display has a driving substrate with bottom electrodes and light-shielding layers between the electrodes. Micro-LED strips of different colors are bonded to the substrate, with the shielding layers spacing them apart. This prevents light leakage and color mixing between the strips.

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Micro-LED display that can sustain high brightness without overheating, which can lead to color degradation and reduced lifetime. The display uses micro-caps to insulate the tiny LEDs from the substrate thermally. The micro-caps create sealed chambers around each LED that can be filled with gas or vacuum. This prevents heat buildup and protects the color conversion layers. The display also has color material layers on the micro-caps to enhance color performance.

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Micro-LED display production with improved subpixel isolation to prevent crosstalk and color mixing. Opaque isolation walls are formed between the subpixels using a multi-step deposition and etching process. This isolates the micro-LEDs and color conversion layers to maintain color purity. The walls are opaque, which blocks light transmission between subpixels. This prevents adjacent subpixels from being illuminated and cured during manufacturing. The opaque walls allow UV micro-LEDs to be used with color conversion without crosstalk. The walls are formed by depositing and etching multiple layers to create vertical walls higher than the subpixels.

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Micro-LED display panel with reduced color shift at oblique angles by using differently sized light-shielding walls around micro-LEDs of different colors. The light shielding walls control the light emission angles to match more closely across colors, reducing color shifts when viewed off-axis.

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A patterned substrate design for producing micro-LED displays with improved epitaxial layer thickness uniformity and LED chip performance. The substrate has grooves that catch excess material during epitaxial growth, preventing uneven layer thicknesses that cause wavelength variation. The grooves are selectively etched into the substrate, and excess epitaxial material is collected to ensure a uniform layer. This improves LED performance by reducing variability in color and brightness.

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A technique to attach downconverter layers to LED dies that enables high-resolution displays and lighting systems with precise color control. The method involves using a temporary transfer layer with downconverter pixels adhered to a release liner. The transfer layer is brought into contact with the LED dies at elevated temperatures, where the adhesive becomes sticky. Once cooled, the release liner is removed, leaving the downconverter pixels attached to the LEDs. The pixels contain downconverter materials like phosphors for color conversion. This allows the downconverter layer to be accurately applied to the LED dies in a single step without pick-and-place assembly.

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Improved display structures that enable higher performance, efficiency and customization of micro-LED displays through optimizing the LED structure and interconnects. The improved display structures can extract more light, customize the color and angular output, and enhance heat sinking. The main idea is to tune micro-LED properties by patterning and releasing the LED layer from the growth substrate then bonding it to a different substrate with customized contacts. The micro-LED array is grown on a substrate, patterned and released, then bonded to a transparent carrier substrate with individually addressable contacts for each LED. This allows optimization of the LED structure and interconnects to improve light extraction, emission angle, color conversion, and heat sinking compared to traditional micro-LED displays.

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Method for optimizing micro-LED display performance by independently controlling the emission time and duty cycle of each subpixel in a pixel to improve color accuracy and power consumption without affecting the gamma.

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Controlling subpixels of microLED displays to independently adjust their emission time and duty cycle. This enables precise color calibration and optimization of power consumption and dynamic range.

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Process for manufacturing optoelectronic devices such as LEDs or micro-LEDs with improved color stability and reliability. The process involves applying and curing multiple layers of a formulation containing a silazane polymer and wavelength converting materials onto the device precursor. The silazane polymer acts as a binder to encapsulate the converting materials. By layering and curing in a specific order, the color point can be precisely adjusted. The silazane binder provides barrier properties and stability to the converters.

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Micro-LED display system and method for improving dynamic range, power consumption and color and gamma correction of the micro LED display. The system uses independent control of emission time and duty cycle for each subpixel in a pixel to optimize color accuracy without affecting gamma correction. This allows precise control over color balance and brightness levels in the display. The duty cycles and emission times are adjusted to tune the display color without affecting the gamma.

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A micro LED display pixel with multiple vertically stacked LEDs emitting different colors. The pixel has two or more LED layers stacked on top of each other, such as red, green, and blue LEDs. The layers are connected with transparent bonding layers. The LEDs in each layer overlap laterally to form a combined light path. This allows the pixel to emit multiple colors from the same area while maintaining resolution. The stacked LED layers are vertically connected to pixel drivers on the substrate. The pixel is fabricated by growing and stacking the LED layers, bonding them together, and connecting to the drivers.

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High efficiency microLED displays with improved long-wavelength emission, such as red and green, by optimizing the active region of the microLEDs. The active layer of the LEDs contains indium gallium nitride (InGaN), but unlike conventional LEDs, the active layer is sandwiched between barrier layers made of specific materials like gallium scandium nitride (GaScN) or GaN/AlGaN. This design prevents electron-hole separation and boosts quantum efficiency for long wavelength emissions.

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