In-Display Fingerprint Exposure Control for Fast Authentication
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Solution Overview
Problem
Existing fingerprint-on-display collection methods face challenges in obtaining correctly exposed fingerprint images under varying light conditions, leading to inefficient identity authentication and poor user experience due to fixed exposure times or slow adjustment of exposure times.
Innovation Solution
A method that calculates exposure time based on interface and screen brightness parameters, adjusts exposure time dynamically to achieve correct exposure, and fine-tunes exposure time for optimal fingerprint image capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed exposure time is used for fingerprint collection, then device complexity is reduced, but correctly exposed fingerprint images cannot be obtained under light source fluctuation or strong light scenarios, affecting authentication efficiency
Solution Approach 1:
The patent implements dynamic exposure time adjustment by calculating the first exposure time based on real-time screen brightness parameters (brightness bar setting order, DBV order, ELVSS voltage, display mode) and interface factors. This allows the exposure time to adapt to varying light conditions rather than remaining fixed, resolving the contradiction between simplicity and reliability.
Solution Approach 2:
The patent changes the exposure time parameter dynamically based on screen brightness parameters and interface characteristics. By calculating the first exposure time using these varying parameters and then correcting it to obtain the second exposure time, the system adapts to different lighting conditions and interface states, improving fingerprint image acquisition reliability without requiring complex hardware modifications.
2Reliability
If automatic adjustment of exposure time is implemented, then correctly exposed fingerprint images can be obtained under varying light conditions, but exposure time adjustment rate is slow and authentication efficiency is reduced
Solution Approach 1:
The patent performs preliminary calculation of the first exposure time based on screen brightness parameters and interface factors before actual fingerprint capture. This pre-calculation allows the system to have a head start in determining appropriate exposure settings, reducing the need for iterative adjustments during authentication and thereby improving speed while maintaining accuracy.
Solution Approach 2:
The patent incorporates a correction mechanism where the first exposure time is corrected based on calibration data to obtain the second exposure time. This feedback loop ensures high accuracy in exposure time determination, allowing the system to achieve correct exposure in fewer attempts and thus improving overall authentication speed while maintaining reliability.
3Productivity
If exposure time is calculated based on screen brightness parameters and interface factors, then the speed of obtaining correctly exposed fingerprint images is improved, but calculation complexity increases
Solution Approach 1:
The patent uses the display driver IC to serve multiple functions: it controls screen brightness display and simultaneously provides brightness parameters (DBV order, ELVSS voltage) for exposure time calculation. This multi-functionality allows the system to perform complex calculations without adding separate dedicated hardware, thus improving acquisition speed while limiting complexity increase.
Solution Approach 2:
The system uses its own existing operational parameters (screen brightness settings, display mode, interface characteristics) to calculate the exposure time, rather than requiring external sensors or additional measurement devices. This self-service approach enables sophisticated exposure time optimization without proportionally increasing device complexity.
Data Source
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AI summary
A fingerprint-on-display collection method and an electronic device are provided. In the method, a first interface and a screen brightness related parameter are obtained, where the screen brightness related parameter is a parameter that affects screen brightness in the electronic device, and the first interface is an interface displayed on a screen when fingerprint collection is performed; first exposure time is calculated based on the first interface and the screen brightness related parameter; and fingerprint collection is performed based on the first exposure time to obtain a first fingerprint image. This application can improve an adjustment speed of exposure time, thereby improving a speed at which the electronic device collects a correctly exposed fingerprint image, and improving user experience.