Sensing devices

Abstract

The present disclosure discloses a sensing device, comprising a sensor configured to convert a sound signal into an electrical signal, the sensor having a first resonant frequency; and a resonant system including a vibration pickup unit and configured to generate a vibration in response to a vibration of a housing of the sensing device. The vibration pickup unit may include at least an elastic diaphragm and a mass block. The elastic diaphragm may be connected to the housing the sensing device through a peripheral side of the elastic diaphragm. The mass block may be at least made of a polymer material. A first acoustic cavity may be defined between the elastic diaphragm and the sensor. When the housing of the sensing device generates a vibration in response to an external sound signal, the elastic diaphragm and the mass block may generate a vibration in response to the vibration of the housing of the sensing device. The elastic diaphragm may cause a sound pressure change in the first acoustic cavity during a vibration process, and the sensor may convert the external sound signal into an electrical signal based on the sound pressure change in the acoustic cavity. The resonant system may provide at least one second resonant frequency to the sensing device. The second resonant frequency may be lower than the first resonant frequency.

1 . A sensing device, comprising
 a sensor configured to convert an acoustic signal into an electrical signal, the sensor having a first resonant frequency; and   a resonant system including a vibration pickup unit configured to generate a vibration in response to a vibration of a housing of the sensing device, the vibration pickup unit including at least an elastic diaphragm and a mass block, the elastic diaphragm being connected to the housing of the sensing device through a peripheral side of the elastic diaphragm, and the mass block being at least made of a polymer material; wherein   a first acoustic cavity is formed between the elastic diaphragm and the sensor, when the housing of the sensing device generates a vibration in response to an external sound signal, the elastic diaphragm and the mass block generate a vibration in response to the vibration of the housing of the sensing device, the elastic diaphragm causes a sound pressure change in the first acoustic cavity during a vibration process, and the sensor converts the external sound signal into an electrical signal based on the sound pressure change of the first acoustic cavity; and   the resonant system provides at least one second resonant frequency to the sensing device, and the second resonant frequency is lower than the first resonant frequency.   
     
     
         2 . The sensing device of  claim 1 , wherein the elastic diaphragm is a film structure at least made of a polymer material. 
     
     
         3 . The sensing device of  claim 2 , wherein the elastic diaphragm and the mass block are made of a same material. 
     
     
         4 . The sensing device of  claim 1 , wherein a Young's modulus of the elastic diaphragm is within a range of 1 Mpa-10 GPa. 
     
     
         5 . The sensing device of  claim 1 , wherein a tensile strength of the elastic diaphragm is within a range of 0.5 Mpa-100 MPa. 
     
     
         6 - 7 . (canceled) 
     
     
         8 . The sensing device of  claim 4 , wherein the elastic diaphragm is a multi-layer composite film structure. 
     
     
         9 . The sensing device of  claim 8 , wherein stiffnesses of at least two layers of the multi-layer composite film structure are different. 
     
     
         10 . The sensing device of  claim 1 , wherein a contact area of the mass block with the elastic diaphragm is less than a projection area of the mass block on the elastic diaphragm. 
     
     
         11 . The sensing device of  claim 1 , wherein the mass block includes a plurality of sub-mass blocks separated from each other, and the plurality of sub-mass blocks are distributed in different regions of the elastic diaphragm. 
     
     
         12 . The sensing device of  claim 1 , wherein the elastic diaphragm at least divides a cavity inside the housing into the first acoustic cavity and a second acoustic cavity, the elastic diaphragm includes at least one first hole, and the at least one first hole enables fluid communication between the first acoustic cavity and the second acoustic cavity. 
     
     
         13 . The sensing device of  claim 12 , wherein the at least one first hole is located in a region on the elastic diaphragm not covered by the mass block. 
     
     
         14 . The sensing device of  claim 12 , wherein the mass block includes at least one second hole, and the at least one second hole is in fluid communication with the at least one first hole. 
     
     
         15 . The sensing device of  claim 14 , wherein a diameter of the at least one first hole or the at least one second hole is within a range of 0.01 μm-40 μm. 
     
     
         16 . The sensing device of  claim 15 , wherein the elastic diaphragm further includes at least one elastic layer, and the elastic layer is located in a region on the elastic diaphragm not covered by the mass block. 
     
     
         17 . The sensing device of  claim 16 , wherein a thickness of the at least one elastic layer is within a range of 0.1 μm-100 μm. 
     
     
         18 . The sensing device of  claim 1 , wherein a filler with fluidity is arranged in at least one second acoustic cavity different from the first acoustic cavity of the sensing device, and a kinematic viscosity of the filler is within 20000 cst. 
     
     
         19 . The sensing device of  claim 1 , wherein a sensitivity difference between a trough between a first resonant peak corresponding to the first resonant frequency and a second resonant peak corresponding to the second resonant frequency and a peak value of a higher one of the first resonant frequency and the second resonant frequency is not greater than 30 dBV. 
     
     
         20 . The sensing device of  claim 1 , wherein a difference between a minimum sensitivity in a frequency range below the second resonant frequency and a sensitivity of a peak value of a resonant peak corresponding to the second resonant frequency is not greater than 30 dBV. 
     
     
         21 . The sensing device of  claim 1 , wherein a frequency difference Δf 1  between the first resonant frequency and the second resonant frequency is within a range of 200-15000 Hz. 
     
     
         22 . The sensing device of  claim 21 , wherein a ratio of the frequency difference Δf 1  to the first resonant frequency is within a range of 0.03-8.