Under-display Sensor with Polarization Layers for Full-front Display Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electronic devices with displays that occupy the entire front surface, it is challenging to integrate a commercially-available proximity-illuminance sensor due to the difficulty in securing a position for the sensor.
Innovation Solution
An under-display sensor is provided, which includes an optical sensor with an emitter and a receiver, a sensor polarization layer, and a sensor retardation layer. These components convert sensing light into circularly-polarized light to pass through the display polarization layer, allowing for the detection of externally-reflected light while minimizing internal reflection errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a display occupies the entire front surface of an electronic device, then the display area is increased, but it becomes difficult to secure a position for placing a proximity-illuminance sensor
Solution Approach 1:
The optical sensor is integrated beneath the display structure, nesting the sensor within the display assembly. The sensor package is positioned in a region where the display structure allows optical communication while maintaining the full-front display appearance, effectively hiding the sensor within the display's structural envelope.
Solution Approach 2:
The solution moves the sensor from the traditional front surface plane to a subsurface position in the vertical dimension. By placing the sensor beneath the display at a controlled distance, the system maintains full-front display visibility while creating a new spatial layer for sensor integration that doesn't compromise the display area.
2Adaptability or versatility
If an optical sensor is placed under the display, then the sensor can be integrated in full-front display designs, but internal reflection from the display structure interferes with sensing accuracy
Solution Approach 1:
A polarization layer is introduced as an intermediary optical element between the sensor and the display structure. This polarization layer, combined with retardation layers, acts as a mediator that selectively transmits sensing light while blocking internally-reflected light, thereby resolving the interference problem without requiring changes to the fundamental under-display sensor configuration.
Solution Approach 2:
The system utilizes polarization state changes of light as it interacts with the display structure. By analyzing the polarization parameters of returned light and comparing them against expected patterns, the system can distinguish between valid sensing reflections and spurious internal reflections, thereby maintaining measurement precision despite the complex optical environment.
3Adaptability or versatility
If a sensor package is provided at a predetermined distance from the display, then the sensor can be integrated under the display, but the structure becomes more complex
Solution Approach 1:
The sensor package is merged with the display assembly as an integrated unit. The sensor, its support structure, and the optical coupling elements are combined into a single packaged component that is installed as one unit within the display structure, reducing the number of separate parts and simplifying the overall assembly process.
Solution Approach 2:
The under-display sensor package is designed to serve multiple functions: proximity sensing, illuminance sensing, and potentially other optical sensing capabilities. This multi-functional design consolidates what would otherwise require multiple separate sensor packages, thereby reducing overall structural complexity while maintaining integration under the display.
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
The under-display sensor effectively enables the detection of ambient light and proximity measurements in electronic devices with full-front display designs, improving the device's functionality without compromising the display's visibility.
Implementation Method 1
a sensor polarization layer, being disposed over the optical sensor and having a polarization axis inclined at a first angle
Implementation Method 2
a sensor retardation layer, being disposed over the sensor polarization layer and having a slow axis inclined at the first angle with respect to the polarization axis
Implementation Method 3
the sensor circularly-polarized light for sensing is converted into a display linearly-polarized light for sensing with a same polarization axis as the polarization axis of the display polarization layer by the display retardation layer
Implementation Method 4
a display polarization layer, both being disposed over the pixel
Implementation Method 5
a receiver configured for detecting an externally-reflected light reflected from an object and returned by the sensing light
Data Source
AI summary
Under-display sensor provided. The under-display sensor includes an optical sensor, having an emitter configured for emitting a sensing light and a receiver configured for detecting an externally-reflected light reflected from an object and returned by the sensing light, a sensor polarization layer, being disposed over the optical sensor and having a polarization axis inclined at a first angle, and a sensor retardation layer, being disposed over the sensor polarization layer and having a slow axis inclined at the first angle with respect to the polarization axis.