Partial Fingerprint Sensor Activation for Power Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fingerprint detection systems face high power consumption due to the involvement of host systems and the need to activate large fingerprint sensors across touch-sensitive surfaces, which increases energy usage and reduces battery life in devices.
Innovation Solution
An electronic assembly with a touch-sensitive surface and a fingerprint sensor, featuring two controller circuits that independently activate and manage the fingerprint sensor, allowing for partial activation only at the user's touch position, reducing computational resource usage and power consumption by minimizing host system involvement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the fingerprint sensor is made as large as the touchscreen to enable fingerprint scanning on any part of the surface, then the versatility and user convenience are improved, but the power consumption increases significantly
Solution Approach 1:
The fingerprint sensor is divided into multiple independently controllable segments or zones. Instead of activating the entire large sensor, only the specific segment corresponding to the user's finger position is activated. This segmentation allows the system to maintain large coverage area while consuming minimal power by activating only necessary portions.
Solution Approach 2:
The system activates only the local region of the fingerprint sensor where the user's finger is detected, rather than the entire sensor area. This local quality approach ensures that power consumption is concentrated only where needed, maintaining versatility while reducing overall energy usage.
2Measurement precision
If the host system with CPU is involved in all fingerprint scanning operations, then the processing capability and accuracy are improved, but the power consumption increases
Solution Approach 1:
The fingerprint processing functionality is extracted from the host system and implemented in dedicated hardware circuits on the fingerprint sensor itself. This extraction allows fingerprint detection and basic processing to occur independently without involving the power-hungry CPU, while still maintaining detection accuracy through specialized hardware optimization.
Solution Approach 2:
The fingerprint sensor is equipped with self-service capabilities including on-sensor processing circuits that can perform fingerprint detection, template matching, and basic authentication operations independently. This self-service approach eliminates the need for continuous host system involvement, significantly reducing power consumption while maintaining functional accuracy.
3Ease of operation
If standard fingerprint sensor implementations include a host system with built-in driver unit, then the control capability is improved, but the power consumption increases due to constant host system involvement
Solution Approach 1:
The control functions previously separated in the host system driver unit are merged directly into the fingerprint sensor's onboard circuits. This merging integrates control capability at the sensor level, allowing the sensor to operate autonomously without requiring continuous host system control, thereby reducing power consumption while maintaining ease of operation.
Data Source
AI summary
Electronic assembly and method (100) for detecting user's fingerprints, comprising a touch-sensitive surface (110) configured to register user touch; a fingerprint sensor (120) for detecting user's fingerprints on at least a part of the touch-sensitive surface; a first controller circuit (CU1) configured to activate the fingerprint sensor and receive fingerprint information from the fingerprint sensor and a second controller circuit (CU2) configured to detect the position and/or movement of a user's finger on (154) or above (152) the touch-sensitive surface in response to signals from the touch-sensitive surface. The electronic assembly further comprises a host system (CPU) connected to the first and second controller circuits, where the host system comprises circuitry for processing information received from the first and second controller circuits. The first controller circuit configured to receive information from the second controller circuit related to the current position (142, 152) and/or movement (v) of the user's finger on or above the touch-sensitive surface and activate a portion (165) of the fingerprint sensor on which to perform fingerprint reading.