Ultrasonic fingerprint sensor with a contact layer of non-uniform thickness
US11460957B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2021 |
| Grant date | Oct 4, 2022 |
| Priority date | — |
| Expiry date | Mar 8, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/87
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An ultrasonic sensor includes a two-dimensional array of ultrasonic transducers, a contact layer, a matching layer between the two-dimensional array and the contact layer, where the matching layer has a non-uniform thickness, and an array controller configured to control activation of ultrasonic transducers during an imaging operation for imaging a plurality of pixels within the two-dimensional array of ultrasonic transducers. During the imaging operation, the array controller is configured to activate different subsets of ultrasonic transducers associated with different regions of the two-dimensional array of ultrasonic transducers at different transmission frequencies, where the different frequencies are determined such that a thickness of the matching layer at a region is substantially equal to a quarter wavelength of the first transmission frequency for the region. The array controller is also configured to combine the plurality of pixels into a compound fingerprint image that compensates for the non-uniform thickness of the matching layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.