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JP-2026074618-A - Vibration detection device, vital sensor, piping sensor

JP2026074618AJP 2026074618 AJP2026074618 AJP 2026074618AJP-2026074618-A

Abstract

[Challenge] To achieve both the suppression of sensitivity decrease due to increased gap and further improvement of sensitivity. [Solution] The vibration detection device according to the present invention comprises a plurality of vibrating parts 10A to 10D arranged point-symmetrically, and a support part 12 that supports the plurality of vibrating parts 10A to 10D so that they can vibrate, wherein the plurality of vibrating parts 10A to 10D have a first part 31 extending in a first direction P from a fixed part 33 fixed to the support part 12, and a second part 32 connected to the first part 31 at the tip 31b side in the first direction P and extending in a second direction Q different from the first direction P, and having a wider width at the tip 32b side in the second direction Q than at the base end 32a side connected to the first part 31. [Selection Diagram] Figure 3

Inventors

  • 藤島 正幸

Assignees

  • 株式会社リコー

Dates

Publication Date
20260507
Application Date
20241021

Claims (9)

  1. Multiple vibrating parts arranged symmetrically, The system includes a support portion that supports the plurality of vibrating parts so that they can vibrate, The aforementioned multiple vibrating parts are A first portion extending in a first direction from the fixing portion fixed to the support portion, A vibration detection device characterized by having a second portion which is connected to the first portion at the tip end in the first direction and extends in a second direction different from the first direction, and which is wider at the tip end in the second direction than at the base end end connected to the first portion.
  2. The vibration detection device according to claim 1, wherein the first direction and the second direction are opposite to each other.
  3. The vibration detection device according to claim 1, wherein the length from the end of the connection portion between the first portion and the second portion on the fixing side to the furthest point toward the fixing portion is in the range of 0.25 to 0.75 times the length from the end of the connection portion between the second portion and the first portion on the fixing side to the furthest point toward the tip side in the second direction.
  4. The vibration detection device according to claim 1, wherein, among the adjacent vibrating parts, the base end of the second portion of one vibrating part and the tip end of the second portion of the other vibrating part are arranged to face each other.
  5. The first and second portions each have a piezoelectric film and two electrodes provided so as to sandwich the piezoelectric film. The vibration detection device according to claim 1, wherein wiring is connected to the two electrodes of either the first part or the second part.
  6. The first and second portions each have a piezoelectric film and two electrodes provided so as to sandwich the piezoelectric film. The electrode provided on one side of the piezoelectric film in the first portion and the electrode provided on the side of the piezoelectric film in the second portion facing the opposite side are connected via wiring. The vibration detection device according to claim 1, wherein the electrode provided on the other surface of the piezoelectric film in the first portion and the electrode provided on the surface of the piezoelectric film in the second portion facing away from the other surface are connected via wiring.
  7. The vibration detection device according to claim 1, wherein the first portion extends in the first direction without bending in a direction intersecting the first direction from one end to the other end opposite to the first direction.
  8. A vital sensor equipped with the vibration detection device described in claim 1.
  9. A piping sensor equipped with the vibration detection device described in claim 1.

Description

This invention relates to a vibration detection device, a vital sensor, and a piping sensor. As a vibration detection device, piezoelectric vibration detection devices are known, which detect vibrations by converting the displacement of a piezoelectric element caused by vibration into an electronic signal. For example, Patent Document 1 (Japanese Patent No. 5936154) proposes a piezoelectric transducer equipped with multiple cantilever beams that convert sound pressure into electronic signals. In configurations with multiple cantilever beams, a problem arises when residual stress causes warping in the cantilever beams, increasing the gaps between them and reducing the sensitivity of vibration detection. To address this problem, Patent Document 1 proposes a configuration in which the beam ends of multiple cantilever beams converge at a common point without contact. This configuration is said to suppress the decrease in sensitivity that occurs with increasing gaps between cantilever beams. However, the piezoelectric transducer described in Patent Document 1 had room for improvement in terms of further enhancing sensitivity. This is a plan view of a vibration detection device according to the first embodiment of the present invention.This is a cross-sectional view of the vibration detection device along the line A1-A1 in Figure 1.This is a plan view showing an enlarged portion of a vibration detection device according to the first embodiment of the present invention.This is a cross-sectional view showing the case where warping occurs in the section along line A1-A1 in Figure 1.This is a plan view showing the detection electrode wiring structure of a vibration detection device according to a second embodiment of the present invention.This is a schematic cross-sectional view showing the detection electrode wiring structure of a vibration detection device according to a second embodiment of the present invention.This is a plan view showing the detection electrode wiring structure of a vibration detection device according to a third embodiment of the present invention.This is a schematic cross-sectional view showing the detection electrode wiring structure of a vibration detection device according to a third embodiment of the present invention.This is a plan view showing the detection electrode wiring structure of a vibration detection device according to the fourth embodiment of the present invention.This is a schematic cross-sectional view showing the detection electrode wiring structure of a vibration detection device according to the fourth embodiment of the present invention.This is a diagram illustrating the deflection angle of a cantilever beam.This figure shows an example of a model of a vibrating part.This figure shows another example of a model of a vibrating part.This figure shows a model with improved sensitivity in the vibration section.This figure shows the model of the vibrating part that was simulated.This figure shows the simulation results of the amount of deflection when the same sound pressure is applied to each of the models in Figure 15.This diagram illustrates the model used to simulate the resonant frequency.This figure shows the simulation results of the sensitivity when the same sound pressure is applied to each of the models in Figure 17.This figure compares the center of gravity of a rectangular vibrating section model and a vibrating section model whose width increases from the fixed end towards the tip.This is a diagram illustrating the model used to simulate the resonant frequency.This figure shows the simulation results for the resonant frequency.This is a plan view showing a first modified example of the vibrating section.This is a plan view showing a second modified example of the vibrating section.This figure shows an example of applying the vibration detection device according to the present invention to a vital sensor.This figure shows an example of applying the vibration detection device according to the present invention to a piping sensor.This is a plan view of a piezoelectric MEMS microphone related to a comparative example.This is a cross-sectional view showing the case where warping occurs in the section along line A2-A2 in Figure 26. The embodiments for carrying out the invention will be described below with reference to the drawings. In the description of the drawings, identical elements will be denoted by the same reference numeral, and redundant explanations will be omitted. <Types of MEMS microphones> First, let's explain the types of MEMS microphones, which are an example of vibration detection devices. A MEMS microphone is a device that receives external vibrations, such as sound waves, at a vibrating part and converts the displacement of that part into an electrical signal. For example, MEMS microphones used to measure audible sounds are mainly used in audio equipment, home appliances, and smartphones. Furthermore, new applications for MEMS microphones are being pr