Fingerprint Identification Panel Light Shielding Electrode
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Solution Overview
Problem
Conventional fingerprint identification panels have relatively low identification sensitivity, requiring a thin cover plate and are inefficient in distinguishing valley and ridge portions of a fingerprint.
Innovation Solution
A fingerprint identification panel with a photoelectric converter unit, including a light shielding electrode, a second electrode, and a photoelectric converter layer, where the light shielding electrode is located between the photoelectric converter layer and the base substrate, enhancing light shielding and capacitance difference between valley and ridge portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional fingerprint identification panel structure is used, then the device structure is simple, but the identification sensitivity is low
Solution Approach 1:
The light shielding electrode is nested within the photoelectric converter unit structure, positioned between the photoelectric converter layer and the base substrate. This nested arrangement integrates light shielding functionality into the existing panel architecture without adding separate external components, thereby improving identification sensitivity while controlling structural complexity
Solution Approach 2:
The light shielding electrode acts as an intermediary element that mediates between the incident light and the photoelectric converter layer. By positioning the light shielding electrode at the intermediate position between the base substrate and the photoelectric converter layer, it controls light transmission and enhances the capacitance difference between valley and ridge portions, improving measurement precision
2Measurement precision
If the cover plate is made thin to improve sensitivity, then the identification sensitivity increases, but the mechanical strength and protection capability decrease
Solution Approach 1:
The patent replaces reliance on mechanical thinning of the cover plate with an optical/electrical mechanism. The light shielding electrode creates electrical field differences that enhance sensitivity through capacitance variation between valley and ridge portions, substituting mechanical structural optimization with an electromagnetic field-based sensing mechanism
3Measurement precision
If conventional electrode structures are used, then the manufacturing process is simple, but the capacitance difference between valley and ridge portions is insufficient
Solution Approach 1:
The light shielding electrode is selectively positioned only in specific regions between the photoelectric converter layer and base substrate, creating localized variations in electrical field distribution. This local quality enhancement focuses the capacitance difference generation at critical sensing points, improving measurement precision without requiring complex electrode patterns across the entire panel
Solution Approach 2:
The patent employs a composite electrode structure combining the light shielding electrode with the photoelectric converter layer and underlying base substrate. This composite arrangement creates multiple interfaces and material boundaries that enhance electrical field modulation, generating sufficient capacitance difference between valley and ridge portions through the interaction of different materials
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
Increases the sensitivity of fingerprint identification by enhancing the capacitance difference between valley and ridge portions, improving the accuracy of fingerprint recognition.
Implementation Method 1
a photoelectric converter layer (5), wherein the photoelectric converter layer (5) is located between the light shielding electrode (10) and the second electrode (4)
Implementation Method 2
the light shielding electrode (10) is located between the photoelectric converter layer (5) and the base substrate (7)
Implementation Method 3
a driving electrode (1) and a sensing electrode (2) insulated from and intersecting with each other are provided between the base substrate (7) and the cover plate (8)
Data Source
AI summary
A fingerprint identification panel and a preparation method thereof, a driving method and a fingerprint identification device are provided. A driving electrode and a sensing electrode are provided between a base substrate and a cover plate, the driving electrode and the sensing electrode intersecting with each other define an identification unit, a photoelectric converter unit is provided in the identification unit. The photoelectric converter unit includes a light shielding electrode, a second electrode, and a photoelectric converter layer located between the light shielding electrode and the second electrode. The light shielding electrode is located between the photoelectric converter layer and the base substrate. The light shielding electrode includes a first electrode, one of the first electrode and the second electrode is electrically connected with the driving electrode, and the other of the first electrode and the second electrode is electrically connected with the sensing electrode.