Ultrasonic Transducer Array Phase Delay for Fingerprint Resolution
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Solution Overview
Problem
Existing ultrasonic transducer systems face challenges in achieving high-resolution fingerprint sensing due to the diffraction of ultrasonic signals, which results in a wider area of transmission rather than a focused beam, making it difficult to accurately sense fingerprints.
Innovation Solution
A two-dimensional array of ultrasonic transducers with phase-delayed transmission, where some transducers are activated at different times to create a focused ultrasonic beam by interfering their signals, allowing for high-resolution sensing by focusing the beam on a specific point or multiple points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasonic transducers transmit signals without phase delay, then the transmission area is wide and covers larger region, but the beam cannot be focused and sensing precision deteriorates
Solution Approach 1:
The two-dimensional array of ultrasonic transducers is divided into multiple independently controllable elements that can be activated selectively. By segmenting the transducer array and controlling individual elements with different phase delays, the system creates focused ultrasonic beams at specific locations, thereby improving fingerprint sensing resolution without requiring the entire array to operate simultaneously.
Solution Approach 2:
Different regions of the transducer array are assigned different phase delay characteristics to create localized focused beams. Each transducer element or subset of elements applies specific phase delays tailored to its position, enabling precise focal point control and high-resolution sensing at specific areas of interest rather than uniform transmission across the entire array.
2Measurement precision
If phase-delayed transmission is applied to focus ultrasonic beam, then sensing accuracy improves, but the system complexity increases
Solution Approach 1:
The system employs periodic phase-delayed transmission sequences where transducers are activated in repeated cycles with specific phase relationships. This periodic activation pattern simplifies the control system by using repetitive timing sequences rather than requiring complex real-time phase adjustment, while still achieving accurate beam focusing for high-precision fingerprint sensing.
Solution Approach 2:
The system controls beam focusing by changing the phase delay parameter of individual transducer elements. By adjusting only the phase parameter rather than requiring mechanical repositioning or complex structural changes, the system achieves accurate beam focusing with relatively simple electronic control, improving sensing accuracy without proportionally increasing system complexity.
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 enables high-resolution fingerprint sensing by concentrating the ultrasonic energy on precise areas, improving the accuracy and detail of fingerprint images captured by the system.
Implementation Method 1
Piezoelectric materials facilitate conversion between mechanical energy and electrical energy. Moreover, a piezoelectric material can generate an electrical signal when subjected to mechanical stress, and can vibrate when subjected to a varying electrical voltage. Piezoelectric materials are widely utilized in piezoelectric ultrasonic transducers to generate acoustic waves based on an actuation voltage applied to electrodes of the piezoelectric ultrasonic transducer.
Implementation Method 2
A two-dimensional array of ultrasonic transducers with phase-delayed transmission, where some transducers are activated at different times to create a focused ultrasonic beam by interfering their signals
Data Source
AI summary
In a method of operating a two-dimensional array of ultrasonic transducers, a plurality of array positions comprising pluralities of ultrasonic transducers of the two-dimensional array of ultrasonic transducers is defined, the plurality of array positions each comprising a portion of ultrasonic transducers of the two dimensional array of ultrasonic transducers. For each array position of the plurality of array positions, a plurality of ultrasonic transducers associated with the respective array position are activated. The activation includes transmitting ultrasonic signals from a first group of ultrasonic transducers of the plurality of ultrasonic transducers, wherein at least some ultrasonic transducers of the first group of ultrasonic transducers are phase delayed with respect to other ultrasonic transducers of the first group of ultrasonic transducers, the first group of ultrasonic transducers for forming a focused ultrasonic beam. The activation also includes receiving reflected ultrasonic signals at a second group of ultrasonic transducers of the plurality of ultrasonic transducers.