Ultrasonic imaging with acoustic resonant cavity

US10274590B2 · kind B2 · utility

Assignee

• QUALCOMM Incorporated · US

Inventors

• Nai-Kuei Kuo · San Jose, US
• Kostadin Dimitrov Djordjev · Los Gatos, US
• Ranjith Ranganathan · San Jose, US
• Nao S. Chuei · San Mateo, US
• Ashish Hinger · Sunnyvale, US
• David William Burns · Minneapolis, US

Key dates

• Filing date: Oct 12, 2017
• Grant date: Apr 30, 2019
• Expiry date: Oct 12, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G06V40/1306
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Techniques describe structures and methods for generating larger output signals and improving image quality of ultrasonic sensors by inclusion of an acoustic cavity in the sensor stack. In some embodiments, an ultrasonic sensor unit may be tuned during manufacturing or during a provisioning phase to work with different thicknesses and materials. In some embodiments, a standing wave signal may be generated using an acoustic cavity in the ultrasonic sensor unit for capturing an ultrasonic image of an object placed on a sensor surface. In some implementations, the ultrasonic sensor may include an ultrasonic transmitter, a piezoelectric receiver, a thin film transistor (TFT) layer and a TFT substrate positioned between the transmitter and the receiver, one or more adhesive layers, and optional cover materials and coatings. The thickness, density and speed of sound of the sensor materials and associated adhesive attachment layers may be used to attain the desired acoustic cavity and improved performance.