MICRODISPLAYS
What is a Microdisplay ?
Microdisplays are miniature screens less than 2 inches in size that offer high resolution in a compact package, making them ideal for devices such as Head Mounted Displays (HMDs), cameras, and projectors. They utilize technologies like LCD, OLED, or LCoS to deliver vibrant colors, high contrast ratios, and efficient performance. Microdisplays are crucial various fields, such as AR/VR for immersive experiences, medical devices for precise data visualization, and consumer electronics for clear image previews. Their applications are diverse and expanding as technology advances.
There are several types of microdisplays, with the most popular and widely used being MicroLED, MicroOLED, and LCD.
To achieve the best quality, microdisplays must meet several criteria, including high resolution, brightness, contrast ratio, color accuracy, and energy efficiency. Additionally, factors such as response time, durability, and cost-effectiveness are essential for their successful implementation in various applications.
Microdisplays criteria :
Brightness
For image clarity
Resolution
For visibility
Contrast Ratio
For visual depth
Color Accuracy
For precise representation
Response Time
For motion blur reduction
Power Comsumption
For operational efficiency
At ELDIM, we are dedicated to helping you to comply those criteria and enhance your Microdisplays with our latest products:
Our product for Microdisplays Measurements
Microdisplays challenges :
RESOLUTION, CONTRAST, BRIGHTNESS
Microdisplays used in AR/VR and wearable devices face several challenges. These include achieving high resolution in limited space, maintaining brightness under varying lighting conditions, ensuring high contrast, managing power consumption, and dealing with heat dissipation. Other critical factors are cost and manufacturability. Balancing resolution with power constraints, ensuring visibility in sunlight, delivering clear content, and producing the displays cost-effectively are crucial for wider adoption. Overcoming these challenges will require continuous innovation and collaboration across the industry.
QUALITY CONTROL
Why is it important to measure Microdisplays ?
Measuring microdisplays is crucial to ensure optimal performance and quality in devices such as AR glasses and projectors. Accurate measurements maintain standards for resolution, brightness, and color accuracy, enhancing the user experience. Quality control through precise measurement helps detect defects early, refine production processes, and support innovation, leading to improved technology.
DETECT DEFAULT PIXELS, UNIFORMITY, RESOLUTION
Measurement of microLED subpixels is crucial for display output evaluation. Challenges include size, variability, and quantity per display, making corrections difficult. Innovative measurement techniques can now identify and adjust individual pixel output for uniform displays. Calibrated high-resolution imaging photometer are recommended for accurate and fast inspection at the pixel and subpixel level in microLED production.
The XSCOPE is an ELDIM equipment specifically designed to capture sharp images of a Device Under Test (DUT) at 4.5x magnification. A unique optical design has been developed to ensure superior image quality, as measured by a Modulation Transfer Function (MTF) greater than 10% for 400 lines per millimeter across the entire image. This design incorporates 12 different lenses, some of which are aspherical, to provide the finest performance within the visible light spectrum.
With the XSCOPE, you can easily measure the brightness of LED pixels on a large scale without the need for complex image fusion techniques. Its ability to measure a wide range of brightness with high precision over a large area makes it perfect for evaluating bright microLED displays built on ASICs. This data will help improve the performance and uniformity of the epitaxial layers and the manufacturing process. In addition, it can be used by the backplane ASIC to compensate for any variations in pixel brightness.
ELDIM XSCOPE photometer allows luminance extraction from LED pixel matrices on a large scale without complex stitching. It analyzes epitaxial impact on electroluminescence at the pixel level, aiding in wafer-level characterization of microLED displays. This enhances epitaxial performance, process maturity, and compensates for pixel brightness non-uniformity using backplane ASIC.
VIEWING ANGLE
Capturing angular light distribution in microdisplays is crucial for consistent, high-quality visuals in applications such as AR and VR. Analysis helps maintain uniform brightness and color accuracy across viewing angles, addressing issues such as glare and color shift. This data informs decisions about optical materials, backlighting, and overall design to enhance the user experience. When integrating microdisplays into devices such as AR headsets, it is important to rely on accurate angular distribution data to ensure optimal visual performance.
The EZLite-N2 enhances microdisplay evualuation with precise angular light distribution measurements for brightness and color accuracy, benefiting high-resolution applications such as AR and VR. Its 300µm iris provides precision and advanced features for detailed measurements, aiding in product development and design optimization in the tech market.
Using EZCONTRAST, with a 100µm iris, offers precise measurement capabilities for microdisplay assessments. It evaluates viewing angle contrast ratios, luminance uniformity, and color accuracy in applications like VR headsets. The equipement supports OLED and LCD technologies, aiding innovation and quality control in display technology, especially for AR headsets.
News about ELDIM's products for Microdisplays
XSCOPE on live at EURODISPLAY
ELDIM‘s team exhibited at Eurodisplay on 19 and 20 of September. Our booth included live demonstrations of our XSCOPE equipment that is dedicated to microdisplays inspection.
Our specialists on site demonstrated the features of the XSCOPE our imaging photometer.
Paper in collaboration with CEA
A joint paper have been written in collaboration with the French Alternative Energies and Atomic Energy Commission (CEA) and ELDIM on “Characterization of GaN-on-Si micro LEDs matrix using new wide field imaging photometer to resolve micro LED pixel size down to 2.5µm.”
The paper highlights our commitment to advancing technology in microdisplays. The paper has been presented at Eurodisplay 2024 in Grenoble.
