VIBRATION SENSOR AND MICROPHONE

Abstract

A vibration sensor and a microphone are provided. The vibration sensor includes a piezoelectric system and a capacitive system. The piezoelectric system includes a vibration component and a piezoelectric sensing component collecting a first electrical signal generated due to deformation of the vibration component. The capacitive system uses the vibration component in the piezoelectric system as a movable capacitive plate and a fixed substrate opposite to the vibration component to form a capacitive vibration sensor. The deformation of the vibration component changes a distance between the vibration component and the fixed substrate. A capacitive sensing component collects a second electrical signal generated due to the distance change. The capacitive sensing component is disposed in a region where the first electrical signal in the piezoelectric system is low, thereby better using space of the vibration sensor, and enhancing the second electrical signal without affecting output of the first electrical signal.

Description

Claims

1. A vibration sensor, comprising: a base;a vibration component, connected to the base and configured to generate a target displacement and a target deformation in response to a vibration of the base;a piezoelectric sensing component, connected to the vibration component and configured to convert the target deformation to a first electrical signal;a fixed substrate, disposed opposite to the vibration component with an interval; anda capacitive sensing component, connected to the fixed substrate and the vibration component, and configured to convert a distance change between the fixed substrate and the vibration component caused by the target displacement to a second electrical signal.

2. The vibration sensor according to claim 1, wherein the vibration component includes: an elastic layer, connected to the base and configured to generate the target deformation in response to an excitation of the vibration of the base; anda counterweight, connected to the elastic layer and configured to generate the target displacement based on the target deformation.

3. The vibration sensor according to claim 2, wherein the base includes a cavity penetrating the base, and at least a part of the vibration component is suspended in the cavity.

4. The vibration sensor according to claim 3, wherein the elastic layer includes: a fixed end, fixedly connected to the base; anda free end, suspended in the cavity, whereinthe counterweight is fixedly connected to the free end of the elastic layer, and suspended in the cavity.

5. The vibration sensor according to claim 4, wherein the elastic layer includes: a plurality of elastic supporting beams, whereinone end of each elastic supporting beam is fixedly connected to the base, andanother end of each elastic supporting beam is connected to the counterweight and suspended in the cavity.

6. The vibration sensor according to claim 4, wherein the elastic layer includes: a suspended membrane structure, whereina periphery of the suspended membrane structure is fixedly connected to the base, anda central region of the suspended membrane structure is connected to the counterweight and suspended in the cavity.

7. The vibration sensor according to claim 2, wherein a position of the capacitive sensing component is aligned with a position of the counterweight, and covers a region corresponding to the counterweight.

8. The vibration sensor according to claim 7, wherein the capacitive sensing component includes: a first capacitive electrode piece, attached to a side of the fixed substrate close to the vibration component; anda second capacitive electrode piece, attached to a side of the vibration component close to the fixed substrate and disposed opposite to the first capacitive electrode piece.

9. The vibration sensor according to claim 8, wherein a position of the second capacitive electrode piece is aligned with a position of the counterweight, and covers a region corresponding to the counterweight.

10. The vibration sensor according to claim 8, wherein the first capacitive electrode piece includes: a position limit protector, disposed on the first capacitive electrode piece and protruding towards a side close to the vibration component, whereinthe position limit protector limits the target displacement of the vibration component to prevent the second capacitive electrode piece from contacting with the first capacitive electrode piece.

11. The vibration sensor according to claim 8, wherein the fixed substrate includes an upper fixed substrate disposed on a side of the vibration component away from the counterweight;the first capacitive electrode piece includes a first upper capacitive electrode piece attached to a side of the upper fixed substrate close to the vibration component; andthe second capacitive electrode piece includes a second upper capacitive electrode piece attached to a side of the vibration component close to the upper fixed substrate and disposed opposite to the first upper capacitive electrode piece.

12. The vibration sensor according to claim 8, wherein the fixed substrate further includes a lower fixed substrate disposed on a side of the vibration component close to the counterweight;the first capacitive electrode piece further includes a first lower capacitive electrode piece attached to a side of the lower fixed substrate close to the vibration component; andthe second capacitive electrode piece further includes a second lower capacitive electrode piece attached to a side of the vibration component close to the lower fixed substrate and disposed opposite to the first lower capacitive electrode piece.

13. The vibration sensor according to claim 7, wherein the piezoelectric sensing component is disposed in at least one of the following regions: a peripheral region close to and surrounding the counterweight; ora region close to a junction between the elastic layer and the base.

14. The vibration sensor according to claim 13, wherein the piezoelectric sensing component includes: a piezoelectric layer, fixedly connected to the base and attached to a surface of the elastic layer, whereinthe piezoelectric layer is configured to generate a voltage based on the target deformation.

15. The vibration sensor according to claim 14, wherein the piezoelectric sensing component further includes: a first piezoelectric electrode layer and a second piezoelectric electrode layer, respectively disposed on surfaces of two sides of the piezoelectric layer and configured to convert the voltage to the first electrical signal, whereinthe first piezoelectric electrode layer and the second piezoelectric electrode layer are positionally aligned with each other, and disposed in at least one of the following regions: the peripheral region close to and surrounding the counterweight, orthe region close to the junction between the elastic layer and the base.

16. The vibration sensor according to claim 15, wherein the first piezoelectric electrode layer includes at least one first piezoelectric electrode piece;the second piezoelectric electrode layer includes at least one second piezoelectric electrode piece; andeach of the at least one first piezoelectric electrode piece is positionally aligned with one or more of the at least one second piezoelectric electrode piece.

17. A microphone, comprising: a housing;a vibration sensor mounted in the housing, wherein the vibration sensor includes: a base,a vibration component, connected to the base and configured to generate a target displacement and a target deformation in response to a vibration of the base,a piezoelectric sensing component, connected to the vibration component and configured to convert the target deformation to a first electrical signal,a fixed substrate, disposed opposite to the vibration component with an interval, anda capacitive sensing component, connected to the fixed substrate and the vibration component, and configured to convert a distance change between the fixed substrate and the vibration component caused by the target displacement to a second electrical signal, whereinthe base is fixedly connected to the housing; anda signal synthesizing circuit, connected to the piezoelectric sensing component and the capacitive sensing component, and configured to synthesize a third electrical signal based on the first electrical signal and the second electrical signal, whereina signal strength of the third electrical signal is greater than a signal strength of the first electrical signal and a signal strength of the second electrical signal.

18. The microphone according to claim 17, wherein the vibration component includes: an elastic layer, connected to the base and configured to generate the target deformation in response to an excitation of the vibration of the base; anda counterweight, connected to the elastic layer and configured to generate the target displacement based on the target deformation.

19. The microphone according to claim 18, wherein the base includes a cavity penetrating the base, and at least a part of the vibration component is suspended in the cavity.

20. The microphone according to claim 19, wherein the elastic layer includes: a fixed end, fixedly connected to the base; anda free end, suspended in the cavity, whereinthe counterweight is fixedly connected to the free end of the elastic layer, and suspended in the cavity.