Array Substrate Refractive Layer for Under-Display Fingerprint Recognition
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Solution Overview
Problem
In display technology, the small gap area between light-emitting devices limits the light-receiving area of photosensitive elements, resulting in weak fingerprint recognition signals due to light-blocking anode layers, which restricts the aperture ratio and overall light collection for fingerprint recognition under the screen.
Innovation Solution
An array substrate design featuring a refractive layer with a higher refractive index than adjacent film layers, positioned between photosensitive devices and light-emitting devices, covers the gap region and increases the light-receiving area by refracting external light, allowing the photosensitive device to be partially located under or between light-emitting devices without reducing the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the photosensitive element is disposed at the gap between light-emitting devices to avoid light-blocking anode layers, then the aperture ratio of the display panel is maintained, but the light-receiving area of the photosensitive element is limited and the fingerprint recognition signal is weak
Solution Approach 1:
The patent transitions the photosensitive element from a two-dimensional planar arrangement (only in gaps) to a three-dimensional configuration by placing it beneath the light-emitting devices. This vertical dimensionality change allows the photosensitive element to receive light that passes through or around the anode layers from below, dramatically increasing its light-receiving area from the limited gap region to the entire pixel area without compromising the display aperture ratio.
Solution Approach 2:
The patent positions the photosensitive element in advance beneath the light-emitting devices during the stacking process, before final assembly. This preliminary placement ensures that the photosensitive element is optimally positioned to capture reflected light from the fingerprint sensing region, allowing it to receive sufficient light intensity for accurate fingerprint recognition while maintaining the display's aperture ratio.
2Area of stationary object
If the photosensitive element is disposed under the light-emitting devices to increase light-receiving area, then the fingerprint recognition signal is strengthened, but the aperture ratio of the display panel is reduced due to light-blocking anode layers
Solution Approach 1:
The patent converts the harmful light-blocking effect of the anode layers into a beneficial configuration. By placing the photosensitive element beneath the light-emitting devices, the anode layers' light-blocking property is transformed into a directional light path: light reflects off the fingerprint, passes through the transparent substrate, and is selectively blocked by the anode layers to create contrast, while the photosensitive element captures the reflected light signal from below, turning the obstruction into a functional sensing mechanism.
Solution Approach 2:
The photosensitive element is pre-positioned beneath the light-emitting devices during the manufacturing stacking process, ensuring optimal alignment before final assembly. This preliminary placement allows the element to capture reflected light effectively while the anode layers maintain their light-blocking function for display purposes, resolving the contradiction between light reception and aperture ratio.
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 design enhances the light-receiving area of the photosensitive device, increasing the intensity of the fingerprint recognition signal, from 15% to 80% of the display area, while maintaining the aperture ratio, thereby improving fingerprint recognition under the screen.
Implementation Method 1
a refractive layer between the photosensitive device and the light-emitting devices. The refractive layer may be at a distance from the photosensitive device, and the refractive layer may cover at least a gap region between the adjacent light-emitting devices. A refractive index of the refractive layer may be larger than a refractive index of a film layer in the gap region
Data Source
AI summary
The present disclosure is related to an array substrate. The array substrate may include a base substrate; a plurality or light-emitting devices on the base substrate; a photosensitive device between the light-emitting devices and the base substrate; and a refractive layer between the photosensitive device and the light-emitting devices. The refractive layer may be at a distance from the photosensitive device, and the refractive layer may cover at least a gap region between the adjacent light-emitting devices. A refractive index of the refractive layer may be larger than a refractive index of a film layer in the gap region between the refractive layer and the photosensitive device, and an orthographic protection of the photosensitive device on the base substrate may at least partially overlap an orthographic projection of the light-emitting devices on base substrate.