Large-Area Fingerprint Sensor Power Reduction via Touch-Block Segmentation
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Solution Overview
Problem
As fingerprint sensors in electronic devices increase in size to match display areas, they also increase power consumption, leading to higher energy demands for devices like smartphones.
Innovation Solution
A display apparatus with a large-area fingerprint sensor that supplies driving signals only to the touched area, utilizing a fingerprint sensor driver to recognize fingerprints by generating and processing ultrasonic waves, reducing power consumption by limiting sensor activation to specific touch blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the fingerprint sensor size is increased to match the display area, then the fingerprint recognition coverage is improved, but the power consumption increases
Solution Approach 1:
The fingerprint sensor is divided into multiple touch blocks (first touch block, second touch block, etc.) corresponding to different sensing gate lines. Only the touched touch block is activated for fingerprint sensing, while other blocks remain inactive. This segmentation allows the large-area sensor to operate with reduced power consumption by processing only the relevant portion where a finger is placed.
Solution Approach 2:
The sensing gate signals are selectively applied only to the specific sensing gate lines corresponding to the touched position. This local activation ensures that power is consumed only in the region where fingerprint recognition is needed, rather than uniformly across the entire large-area sensor, thereby reducing overall power consumption while maintaining recognition capability.
2Adaptability or versatility
If the fingerprint sensor covers the entire display area, then the authentication versatility is improved, but the device power consumption increases
Solution Approach 1:
The fingerprint sensor system dynamically activates only the necessary sensing gate lines based on touch position information from the touch panel. When a user touches a specific area, the system identifies the corresponding touch block and activates only those sensing gate lines, rather than continuously activating all sensing gate lines across the entire display area. This dynamic activation reduces power consumption while maintaining full-area authentication capability.
Solution Approach 2:
The system uses touch panel information to automatically determine which fingerprint sensing region should be activated. The touch panel detects the finger placement position and provides this information to selectively control the fingerprint sensor activation, enabling the system to self-regulate power consumption based on actual user interaction without requiring external control.
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 enhances fingerprint recognition performance while reducing power consumption in both the display apparatus and electronic devices, by only activating the fingerprint sensor at the touched position, thus decreasing overall energy usage.
Implementation Method 1
fingerprint sensors using the ultrasonic type recognize a fingerprint by using a difference between voltages which are generated when ultrasonic waves generated by a plurality of piezoelectric elements are reflected by a ridge and a valley of the fingerprint
Data Source
AI summary
A display apparatus including a large-area fingerprint sensor includes a display panel displaying an image; a touch panel sensing a touch of a finger; a fingerprint sensor including a plurality of fingerprint pixels and recognizing a fingerprint of the finger; a fingerprint sensor driver driving the fingerprint sensor and including a driver driving the fingerprint sensor and a fingerprint recognizer recognizing a fingerprint by using sensing signals received from the fingerprint sensor; and a touch driver driving the touch panel, wherein the driver of the fingerprint sensor driver provides a sensing gate signal to sensing gate lines included in a first touch block determined being touched by touch position information received from the touch driver, among m (where m being an integer of 2 or greater) number of sensing gate lines included in the fingerprint sensor.