Under-Display Optical Sensing with Discrete Light Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical sensing systems for biometric imaging, such as fingerprint recognition, face challenges in efficiently illuminating and capturing high-quality images through display substrates, particularly in thin form factors like mobile devices, due to light loss and interference from display components.
Innovation Solution
The implementation of under-display optical sensing systems with discrete light sources, such as micro-LEDs or dedicated OLED emitters, positioned to provide point-source illumination close to the sensing surface, combined with advanced image processing methods for brightness correction and image stitching, allows for high-contrast imaging of biometric features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a backlight is used to illuminate the sensing region through the display substrate, then the display can provide sufficient illumination, but light loss and interference from display components reduce imaging quality
Solution Approach 1:
The patent extracts the sensing light source function from the display backlight system by introducing separate dedicated light sources (micro-LEDs or OLED emitters) positioned close to the sensing surface. This allows the display backlight to be optimized for display purposes while the separate light sources provide controlled illumination for sensing, reducing light loss and interference.
Solution Approach 2:
The patent implements local quality by placing discrete light sources at specific locations (in opaque regions of the display substrate) close to the sensing surface. This localized illumination approach provides sufficient light intensity where needed for biometric imaging while minimizing overall light loss and interference from display components.
2Measurement precision
If discrete light sources are positioned close to the sensing surface, then optical efficiency and image resolution improve, but device complexity increases
Solution Approach 1:
The patent merges the sensing light source function with the display structure by integrating micro-LEDs or OLED emitters into the display substrate itself. This combination approach improves optical efficiency and image resolution while avoiding the need for separate illumination systems, thereby managing device complexity.
Solution Approach 2:
The patent implements multi-functionality by using the same display substrate to house both display elements and sensing light sources. The display substrate serves dual purposes: displaying visual information and providing structured illumination for biometric sensing, reducing overall device complexity.
3Reliability
If separate sensor light sources are used instead of display backlight, then light interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent implements self-service by having the display substrate provide its own dedicated light sources for sensing functionality. The micro-LEDs or OLED emitters are integrated directly into the display substrate structure, allowing the display to serve its own sensing illumination needs without requiring external or separately manufactured illumination components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances optical efficiency, improves image resolution, and enables the capture of high-quality biometric images by minimizing light loss and interference from display components, while maintaining a compact form factor.
Implementation Method 1
the sensor light source comprises a light emitting diode (LED) disposed over the display substrate, or under the display substrate, or in the display substrate
Implementation Method 2
a detector for detecting light from the sensing region
Data Source
AI summary
Optical sensing systems and methods for imaging objects include under-display optical sensors with one or multiple discrete light sources positioned on, in or under the display. The optical sensors may include an array of optical sensing elements, e.g., photodetectors, arranged in or under the display. The displays include OLED or LCD displays.