In-Display Fingerprint Sensor Ultrasonic Delay Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-display fingerprint sensors with ultrasonic schemes experience recognition errors due to protective films, leading to inconvenience for users as they wait unnecessarily for re-recognition processes, which reduces fingerprint recognition efficiency.
Innovation Solution
An electronic device with a fingerprint sensor positioned under a specified area of the display, where the processor adjusts the sensor settings based on image conditions to optimize image capture and authentication, reducing the number of frames needed for background image capture and enhancing recognition efficiency by adjusting the ultrasonic wave delay in the presence of a protective film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the fingerprint sensor operates in ultrasonic scheme with protective film attached, then the display is protected, but fingerprint recognition accuracy deteriorates due to recognition errors
Solution Approach 1:
The patent adjusts the delay time parameter of the ultrasonic wave based on whether a protective film is detected. When a protective film is present, the delay time is modified to compensate for the additional distance the ultrasonic wave must travel, thereby maintaining accurate fingerprint recognition despite the presence of the protective film layer.
2Measurement precision
If the system captures multiple frames for background image, then image quality improves, but the time required for background image capture increases
Solution Approach 1:
The patent captures a reduced number of frames (e.g., 1 frame) for background image when a protective film is detected, compared to the standard multiple frames (e.g., 3 frames) captured when no protective film is present. This partial action approach accepts slightly reduced image quality in exchange for significantly reduced capture time, which is necessary because the user's finger position may change during the capture period.
3Reliability
If the fingerprint sensor captures more frames during re-recognition, then recognition accuracy improves, but user wait time increases reducing overall efficiency
Solution Approach 1:
The patent reduces the number of frames captured during re-recognition process when a protective film is present. Instead of capturing multiple frames to ensure accuracy, the system captures fewer frames (e.g., 1 frame) to minimize user wait time, accepting a trade-off in recognition accuracy to maintain overall system efficiency and user experience.
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 approach reduces wait times for users during re-recognition processes and improves fingerprint recognition efficiency by quickly capturing background images and adjusting sensor settings to account for protective films, thereby enhancing overall performance.
Implementation Method 1
the fingerprint sensor outputs an ultrasonic wave of a specified frequency toward the specified area
Implementation Method 2
obtains the first image based on a reflective wave corresponding to the ultrasonic wave
Data Source
AI summary
An electronic device includes a display, a fingerprint sensor positioned under a specified area of the display, and a processor. The processor is configured to obtain a first image based on a first input, perform authentication associated with biometric information, when a state of the first image meets a first condition, obtain a second image using the fingerprint sensor, when the state of the first image meets a second condition, adjust a setting of the fingerprint sensor, obtain a third image using the fingerprint sensor adjusted from the first value to a second value, and perform authentication associated with the biometric information based on the second image and the third image.