OLED Fingerprint Module with PN Junction Photocurrent
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Solution Overview
Problem
There is no OLED display integrated with a fingerprint identifying function, which limits the ability to combine display and fingerprint identification capabilities.
Innovation Solution
A fingerprint identifying module is developed, comprising a substrate with a plurality of fingerprint identifying modules arranged as an array, each consisting of a lower electrode, an upper electrode, and a photocurrent generating unit with a PN junction, allowing for the differentiation of fingerprint valleys and ridges through varying light intensities and photocurrent generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional LCD integrates a fingerprint identifying function, then display and fingerprint identifying functions are implemented simultaneously, but OLED display lacks this integrated capability
Solution Approach 1:
The patent merges the fingerprint identifying function with the OLED display structure by integrating a photocurrent generating unit (PN junction) between the upper and lower electrodes. This combination allows the display panel to simultaneously perform display and fingerprint identification functions, resolving the technical contradiction by enabling OLED displays to achieve the adaptability of LCDs while maintaining their own structural advantages.
Solution Approach 2:
The OLED display panel is designed with multi-functionality by incorporating the photocurrent generating unit that can detect light intensity variations from fingerprint ridges and valleys. This universal design enables the same display structure to serve dual purposes: visual display and biometric authentication, thereby improving adaptability without significantly increasing device complexity.
2Measurement precision
If fingerprint identifying module uses photocurrent generating unit with PN junction, then fingerprint valleys and ridges are distinguished through varying light intensities, but manufacturing process becomes more complex
Solution Approach 1:
The fingerprint identifying module is segmented into distinct functional layers: lower electrode, photocurrent generating unit (PN junction), and upper electrode. This segmentation allows each component to be manufactured and optimized independently, with the PN junction specifically designed to detect light intensity variations. The segmented structure achieves high measurement precision for fingerprint differentiation while managing manufacturing complexity through modular fabrication processes.
Solution Approach 2:
The photocurrent generating unit utilizes parameter changes in light intensity to differentiate between fingerprint ridges and valleys. By detecting the varying light intensities that reach the PN junction through the fingerprint patterns, the system achieves high measurement precision. The fabrication process incorporates standard semiconductor manufacturing techniques for creating PN junctions, balancing the ease of manufacture with the required detection precision.
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
Enables the integration of fingerprint identification functionality into OLED displays by distinguishing between fingerprint valleys and ridges through photocurrent feedback, effectively implementing a fingerprint identifying function on OLED display panels.
Implementation Method 1
a photocurrent generating unit between the upper electrode and the lower electrode and connected with both the upper electrode and the lower electrode, the photocurrent generating unit comprises a PN junction
Data Source
AI summary
A fingerprint identifying module, a fabrication method and a driving method for the same, and a display device are provided. The fingerprint identifying module includes a substrate, and a plurality of array-arranged fingerprint identifying modules provided on the substrate. Each of the fingerprint identifying modules includes a lower electrode, an upper electrode, and a photocurrent generating unit connected between the upper electrode and the lower electrode. The photocurrent generating unit includes a PN junction, one end of the PN junction being connected with the upper electrode, and the other end of the PN junction being connected with the lower electrode.