Fingerprint Sensor Force Gesture Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fingerprint sensor navigation methods require users to lift their finger and reposition it for multiple swipe events, making the process inefficient in terms of finger movement.
Innovation Solution
Measuring force value differences across sub-groups of fingerprint sensing elements allows for user input without lifting the finger, enabling 'pointing-stick' or 'gesture control' functionality by estimating force from partial fingerprint images, eliminating the need for additional force sensors and allowing for complex user inputs through combinations of force differences and relative locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional fingerprint sensor navigation methods are used, then the sensor can detect finger touches for basic navigation, but the user must lift and reposition the finger for multiple swipe events, reducing operational efficiency
Solution Approach 1:
The fingerprint sensor array is divided into multiple sub-groups of sensing elements. By measuring force value differences between these segmented sub-groups, the system can detect directional gestures and create multiple navigation events without requiring the user to lift and reposition their finger, thus improving navigation control efficiency and reducing time loss.
2Measurement precision
If force sensors are added underneath fingerprint sensing elements to enable fine force measurement, then force detection precision improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The fingerprint sensor's existing sensing elements serve dual purposes: capturing fingerprint images and measuring applied force. By analyzing the relationship between fingerprint image intensity and applied force, the system derives force measurement capability from the existing sensor infrastructure, eliminating the need for additional force sensors and reducing device complexity.
Solution Approach 2:
The system changes the measurement parameter from purely optical fingerprint image capture to a combined measurement that includes force-induced intensity variations. By detecting changes in fingerprint image intensity caused by varying applied forces, the system achieves force measurement precision without adding separate force sensing hardware.
3Reliability
If the fingerprint sensor processes complete fingerprint images for authentication, then authentication accuracy is maintained, but processing time and computational resources increase
Solution Approach 1:
The system extracts only the necessary sub-group of sensing elements that contain the relevant force measurement data for navigation control. By processing only these specific sub-groups rather than complete fingerprint images, the system reduces computational load and processing time while maintaining the ability to detect user input gestures accurately.
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5C
AI summary
A method for providing user input on an electronic device comprising a fingerprint sensor (3) comprising an array (404) of sensing elements (402). Acquiring (S102) partial fingerprint images of a finger touching a finger touch surface (401 ) of the fingerprint sensor from at least two sub-groups (404a,b,c,d) of sensing element. Determining (S104) a respective force value indicative of a force applied on the finger touch surface at each of the sub- groups of sensing elements when the partial fingerprints were acquired, based on the partial fingerprint images acquired from the respective sub- group of sensing elements. Determining (S106) a force value difference between a pair of the determined force values. Determining (S108) a user input based on the determined force value difference, and based on the relative location between the sub-groups of sensing elements in the pair associated with the force value difference.