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MicroLED Devices Integrating Microlenses May Sharpen the AR Experience

August 15, 2022 by Jake Hertz

MicroLED developer MICLEDI is getting even more granular with microLEDs—now, with integrated microlenses.

While many companies have invested in augmented reality (AR) development, this technology faces several technical challenges preventing widespread adoption. Of these challenges, developing a lightweight, high-performance display is at the top of the list.

One promising technology that may solve this challenge is microLEDs, which offer high-resolution images while simultaneously improving power efficiency. This week, microLED developer MICLEDI Microdisplays made headlines when it announced the so-called industry’s first family of microLEDs that integrate microlenses for beam shaping.

 

MicroLED display module

According to MICLEDI, the microLED display module includes an integrated ASIC with PWM display driving and full chromaticity correction, designed in a sub-40nm CMOS process node. Image used courtesy of MICLEDI

 

Why MicroLEDs Reign Supreme in AR Displays

Today, one of the most popular display technologies in augmented reality headsets is microLEDs.

MicroLED refers to LED technology that is shrunk down to the micrometer scale and placed in an array to create a light engine. In general, a single pixel in a microLED display can measure as small as 50μm—1/100 the size of a conventional LED. An important feature of microLEDs is that they are self-emissive display devices, meaning they do not require a backlight. Instead, they are active devices that project light directly due to electron-hole pair recombination within a semiconductor material.

 

RGB micro-LED microdisplays combined by a trichroic prism

RGB microLED microdisplays combined by a trichroic prism. Image used courtesy of Nature and Xiong et al

 

In the context of augmented reality headsets, the microLED light engine is generally paired with a waveguide structure that directs the emitted light to the viewer’s eyes. In this way, the glasses can take the RGB pixels generated from the microLED display and convert them into a useful image that can be projected directly to the user.

 

The Big Benefits of MicroLEDs

There are many advantages to microLED displays in augmented reality applications.

One is their high energy efficiency compared to other light sources, making them a go-to choice in the light engine of AR glasses. The efficiency of microLEDs conserves AR glasses' battery life and gives off little heat—an important feature for maintaining the reliability of the device and the comfort of the user. 

Beyond efficiency, microLEDs are extremely small light sources. Because of this, microLED arrays can create pixels that are comprised of multiple LEDs per pixel, resulting in high-resolution images. The small size of microLEDs also makes headsets lighter, another important factor for a comfortable user experience.

Finally, microLEDs are an affordable solution since they are based on well-established and scalable semiconductor processes. Hurdling this manufacturing barrier can drive down the costs of the end product, the AR glasses, and expand their adoption.

 

MICLEDI Integrates Microlenses Directly on MicroLEDs

This week, MICLEDI Microdisplays announced a new family of microLED displays for augmented reality applications.

Manufactured on a proprietary 300mm process that is CMOS compatible, the microLED technology consists of a self-contained monolithic microLED module that integrates a control ASIC directly on the wafer. The display consists of FHD RGB arrays, each with 3.0μm pixel pitch, and can reach up to 10,000,000 nits luminance—all with power consumption below 1 W in standard use cases.

 

Micro-lenses allow for greater directionality and control over light.

Microlenses allow for greater directionality and control over light. Image used courtesy of MICLEDI

 

According to MICLEDI, the new family's real value proposition is that it represents the world’s first solution to integrate microlenses directly onto the solution. With the microlenses sitting above the microLEDs, MICLEDI claims they can achieve greater control over the emitted light, directing and beam shaping to their desire. In this way, adding microlenses will help their displays achieve better image quality and power efficiency via improved light-focusing through waveguides. 

MICLEDI designed this display technology to bring better efficiency, performance, and cost to future AR glasses.

 


 

Featured image used courtesy of MICLEDI