US 12,284,481 B2 · Audio speaker and proximity sensor with piezoelectric polymer technology

Abstract

A mobile device includes one or more piezoelectric polymer layers underlying a display. The one or more piezoelectric polymer layers may be electrically driven to operate in either a d33 stretching mode or a d31 bending mode. The mobile device functions as an ultrasonic sensor in the d33 stretching mode and as an audio speaker/microphone or a proximity sensor in the d31 bending mode. The piezoelectric polymer layer operating in the d31 bending mode may be directly mechanically coupled to a display, indirectly mechanically coupled to the display and underlying an ultrasonic sensor stack, or integrated in the ultrasonic sensor stack. Signal performance of the piezoelectric polymer layer operating in the d31 bending mode may be enhanced or modulated by having a larger area, multiple layers, bi-pole or uni-pole driving with multiple layers, one or more stiff adhesives, a spacer layer, one or more mass features, a thin TFT layer, a thick piezoelectric polymer layer, or combinations thereof.

Claims13

Dependent claims

A mobile device comprising:

a platen;
a display underlying the platen;
a thin-film transistor (TFT) layer underlying the display, wherein the TFT layer comprises an array of pixel electrodes, wherein adjacent pixel electrodes are separated by voids or flexible material;
a first piezoelectric polymer layer adjacent to and coupled to the TFT layer;
an electrode layer adjacent to and coupled to the first piezoelectric polymer layer, wherein the first piezoelectric polymer layer is positioned between the electrode layer and the TFT layer, wherein the TFT layer, and the first piezoelectric polymer layer form an ultrasonic sensor configured to operate in a d33 stretching mode;
a second piezoelectric polymer layer underlying the display, wherein the second piezoelectric polymer layer is configured to operate in a d31 bending mode in a second frequency range between about 20 kHz and about 1 MHz to function as a contactless proximity or gesture detector;
and
a stiff epoxy adhesive layer between the TFT layer and the display, wherein the stiff epoxy adhesive has a Young's modulus equal to or greater than about 1.0 GPa.

5 more elements

Dependencies are inferred from the claim text.

Audio speaker and proximity sensor with piezoelectric polymer technology

Life of this patent

Audio speaker and proximity sensor with piezoelectric polymer technology

Life of this patent

Abstract

Claims13