OLED Display Panel With Embedded Light Sensitive Units
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing under-screen optical fingerprint recognition technologies face challenges with low accuracy and efficiency due to long light transmission paths and significant light loss, which affect the recognition process in OLED display panels.
Innovation Solution
The integration of light sensitive units within the OLED module functional layer, where the anode of the organic electroluminescence device is located, reduces light propagation paths and enhances recognition accuracy and efficiency by utilizing the self-illumination properties of OLED pixels without additional light sources, and includes a light blocking layer to improve signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the optical fingerprint recognition module is placed at the back side of the OLED substrate, then the screen ratio is increased and direct contact with fingerprint module is eliminated, but the light transmission path becomes long and light loss increases
Solution Approach 1:
The patent embeds the light sensitive unit within the OLED module functional layer structure, nesting the fingerprint recognition component inside the display module rather than placing it externally on the substrate back side. This nested arrangement shortens the light path while maintaining the under-screen configuration benefits.
Solution Approach 2:
The patent repositions the light sensitive unit from the traditional substrate back side (one dimensional placement) to within the OLED module functional layer (three dimensional integration). This dimensional change allows the sensor to be closer to the light source while maintaining the under-screen configuration.
2Ease of operation
If the optical fingerprint recognition module is placed at the back side of the OLED substrate, then the fingerprint recognition can be performed without direct contact, but the recognition accuracy and efficiency decrease due to light loss
Solution Approach 1:
By nesting the light sensitive unit within the OLED module functional layer, the patent maintains the contactless operation benefit while improving recognition accuracy through reduced light loss. The nested position allows better light collection from the fingerprint.
3Measurement precision
If the light sensitive unit is placed within the OLED module functional layer, then the light transmission path is shortened and recognition accuracy is improved, but the device structure becomes more complex
Solution Approach 1:
The patent merges the fingerprint recognition function with the existing OLED module functional layer structure. By combining these functions in the same structural framework, the patent improves recognition accuracy without adding separate external modules, thus limiting the increase in device complexity.
Solution Approach 2:
The OLED module functional layer serves dual purposes: displaying images and performing fingerprint recognition. This multi-functionality approach allows the same structural layer to accomplish multiple tasks, reducing overall device complexity despite the integrated sensor placement.
4Illumination intensity
If additional light sources are added for fingerprint illumination, then the illumination intensity is increased, but the device complexity and power consumption increase
Solution Approach 1:
The patent utilizes the self-illumination capability of OLED pixels to provide fingerprint illumination. The OLED pixels serve themselves by providing both display function and illumination function, eliminating the need for separate light sources. This self-service approach maintains illumination intensity while reducing device complexity and power consumption.
Solution Approach 2:
The OLED pixels perform multiple functions: displaying images and providing illumination for fingerprint recognition. This multi-functionality eliminates the need for dedicated light sources, reducing device complexity while maintaining sufficient illumination intensity for accurate fingerprint capture.
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 improves the accuracy and efficiency of fingerprint recognition by minimizing light loss and optimizing the use of OLED pixels for illumination, reducing the thickness of the fingerprint recognition module and enhancing sensitivity.
Implementation Method 1
an organic light emitting layer, disposed on the anode layer; a cathode layer, disposed on the organic light emitting layer
Implementation Method 2
configured to receive reflected light generated when light emitted by the organic light emitting layer of the organic electroluminescence device is reflected by a fingerprint, and to transform optical signals into differential electrical signals to form a fingerprint image
Data Source
AI summary
An OLED display panel and an under-screen optical fingerprint recognition method are provided. In the OLED display panel, light sensitive units for optical fingerprint recognition are assembled in an OLED module functional layer and located on a same film layer where an anode of an organic electroluminescence device is located on, and located at gaps between the anodes. Such a structure reduces a path for light propagation, increases intensity of light received by the light sensitive units, and improves accuracy and efficiency in fingerprint recognition.