Optical Fingerprint Module Using OLED Display Light
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Solution Overview
Problem
Existing optical fingerprint modules have limited functionality and application due to their single-purpose design, which restricts their use and increases costs by requiring separate light sources for fingerprint capture.
Innovation Solution
Integration of an Organic Light Emitting Diode (OLED) display panel with an optical fingerprint sensor, where the OLED panel includes light-emitting and non-opaque regions to capture fingerprint images without an external light source, allowing for both fingerprint capture and display functions within a single module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate backlight source is used for fingerprint capture, then fingerprint imaging quality is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges the display panel and fingerprint sensor into a single integrated module, where the display panel's light-emitting regions serve as the light source for fingerprint capture. This eliminates the need for a separate backlight source, reducing device complexity while maintaining imaging quality through the unified optical path.
Solution Approach 2:
The display panel performs dual functions: displaying information and providing illumination for fingerprint capture. The light-emitting regions of the display panel serve both as visual output and as the backlight source for the fingerprint sensor, reducing the need for separate components.
2Measurement precision
If a separate backlight source is used for fingerprint capture, then fingerprint imaging quality is improved, but manufacturing cost increases
Solution Approach 1:
By combining the display panel and fingerprint sensor into one module with shared light-emitting components, the patent reduces the total component count and assembly steps, thereby lowering manufacturing costs while maintaining imaging quality.
Solution Approach 2:
The display panel's light-emitting regions serve dual purposes as both display elements and backlight sources for fingerprint capture, eliminating the need for separate backlight components and reducing overall manufacturing complexity and cost.
3Ease of operation
If the OLED display panel uses light blocking regions for display pixels, then display function is improved, but light transmission for fingerprint capture is reduced
Solution Approach 1:
The patent divides each display pixel into distinct light-emitting regions and light blocking regions. The light-emitting regions provide illumination for fingerprint capture, while the light blocking regions enable display functionality. This segmentation allows both functions to coexist without significant interference.
Solution Approach 2:
Different regions within each display pixel are assigned different optical properties: light-emitting regions are designed to transmit light for fingerprint capture, while light blocking regions are optimized for display contrast. This local differentiation of optical characteristics resolves the conflict between display and sensing functions.
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 integration simplifies the module's structure, reduces costs, and enhances its application range by enabling simultaneous fingerprint capture and display capabilities, ensuring high-quality fingerprint images with uniform light exposure.
Implementation Method 1
an Organic Light Emitting Diode (OLED) display panel, including a third surface, a fourth surface, and an OLED device layer disposed between the third surface and the fourth surface
Implementation Method 2
The optical fingerprint sensor performs photoelectric conversion and signal processing by its inner circuits
Data Source
AI summary
An optical fingerprint module includes: an optical fingerprint sensor having a first surface, a second surface, and a plurality of photosensitive pixels; and an OLED display panel having a third surface and a fourth surface. An OLED device layer is formed between the third surface and the fourth surface; the OLED device layer includes a plurality of display pixels each of which consists of at least one non-opaque region and at least one light blocking region; a light emitting device is provided in the at least one light blocking region; light emitted by the light emitting device at least partially reaches the fourth surface; the light reaching the fourth surface is at least partially used for acquiring a fingerprint image, thereby generating reflective light; the reflective light passes through the non-opaque region, the third surface, the second surface, and enters the plurality of photosensitive pixels.