Sound receiving device

Abstract

The sound receiving device of the present invention is located in a first space, and receives sound generated in a second space separated from the first space by a specified plate, wherein the device comprises: a metal plate; a piezoelectric element fixed to the upper surface of the metal plate; a shell, which is a cylinder with an open upper surface and a lower surface, and whose upper end surface is bonded to the lower surface of the metal plate, and whose lower end surface is bonded to the plate; a vibration pickup terminal housed in the shell, and comprising a foot bonded to the lower surface of the metal plate, an axis extending from the foot in a downward direction, and a front end formed in the lower direction of the axis and in contact with the plate when the shell is bonded to the plate.

Description

Technical Field

[0001] The present invention relates to a sound receiving device which is located in a first space and receives sound generated in a second space which is separated from the first space by a predetermined plate. Background Art

[0002] As a conventional technology of a sound pickup microphone, there is Patent Document 1 (Patent Document 1: Japanese Patent No. 6622638), for example.

[0003] The contact microphone assembly of patent document 1 is a contact microphone assembly that converts mechanical vibration into an electrical signal by pressing a piezoelectric element with a vibration element, and comprises a piezoelectric vibration plate supported in a vibration-capable manner in an assembly housing and a vibrator housed in the assembly housing and arranged above the piezoelectric vibration plate, the vibrator having a spherical portion that abuts against the center portion of the piezoelectric vibration plate, and an elastic component is provided in the assembly housing at least between the piezoelectric vibration plate and the spherical portion of the vibrator.

[0004] For example, if you want to listen to the sound produced outside the car in the car, you need a sound hole, but there are many cases where the car is not equipped with a sound hole for many reasons. In addition, if the reception room and the waiting room of a hospital are separated by glass, etc., a sound hole is also needed to listen to the sound produced in the waiting room in the reception room, but it is often not possible to install a sound hole from the perspective of hygiene. Summary of the invention

[0005] Therefore, an object of the present invention is to provide a sound receiving device which is located in a first space and is capable of receiving sound generated in a second space separated from the first space by a predetermined plate.

[0006] The sound receiving device of the present invention is located in a first space, and receives sound generated in a second space separated from the first space by a specified plate, wherein the device comprises: a metal plate; a piezoelectric element fixed to the upper surface of the metal plate; a shell, which is a cylinder with an open upper surface and a lower surface, and whose upper end surface is bonded to the lower surface of the metal plate, and whose lower end surface is bonded to the plate; a vibration pickup terminal housed in the shell, and comprising a foot bonded to the lower surface of the metal plate, an axis extending from the foot in a downward direction, and a front end formed in the lower direction of the axis and in contact with the plate when the shell is bonded to the plate.

[0007] The sound receiving device of the present invention is located in a first space and can receive sound generated in a second space separated from the first space by a predetermined plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a cross-sectional view of the sound receiving device of Example 1. DETAILED DESCRIPTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. Note that components having the same functions are denoted by the same reference numerals and duplicate descriptions are omitted.

[0010] [Example 1]

[0011] Below, refer to Figure 1 The structure of the sound receiving device 1 of the first embodiment is described. As shown in the figure, the sound receiving device 1 of the present embodiment is located in a first space (e.g., inside a car or indoors), and receives sound generated in a second space (e.g., outside a car or outdoors) separated from the first space by a predetermined plate 9 (e.g., window glass of a car, window glass of a house, a glass plate separating a reception room and a waiting room, an acrylic resin plate, etc.), and includes: a metal plate 11 (functioning as a one-side electrode); a piezoelectric element 12 fixed to the upper surface of the metal plate 11 via an adhesive layer 17; a housing 13, which is a cylindrical shape with an opening on the upper surface and the lower surface (e.g., it can be set to a cylindrical shape, a square cylindrical shape, any number of The housing 13 is a cylindrical housing (in the shape of a tube with a rectangular cross-section), and its upper end surface is bonded to the lower surface of the metal plate 11 via an adhesive layer 14, and its lower end surface is bonded to the plate 9 via an adhesive layer 15; a vibration pickup terminal 16, which is accommodated in the housing 13 and includes a foot 161 (for example, it can be set to a flat disk shape) bonded to the lower surface of the metal plate 11 via an adhesive layer 18, an axis 162 extending from the foot 161 in the downward direction, and a front end 164 (for example, it can be set to a spherical shape or an ellipsoidal shape flattened in the upward and downward directions) formed at the front end in the downward direction of the axis 162 and in contact with the plate 9 when the housing 13 is bonded to the plate 9.

[0012] In order to prevent vibration loss, it is desirable to use a hard adhesive for the adhesive layers 14, 17, and 18. Note that the adhesive layer 15 is not intended to transmit vibration, so a hard adhesive is not necessary, and any adhesive with high adhesion is sufficient.

[0013] like Figure 1 As shown, by making a straight line (single-dash line in the figure) extending from the center of the vibration pickup terminal 16 (point A in the figure) along the long axis direction pass near the center of the piezoelectric element 12 (point B in the figure), the vibration propagating in the vibration pickup terminal 16 can be efficiently transmitted to the piezoelectric element 12.

[0014] like Figure 1 As shown, if a hole 163 extending in the long axis direction of the shaft portion 162 is provided to make the shaft portion 162 hollow, the sound waves propagating in the plate 9 can be efficiently transmitted to the piezoelectric element 12, which is preferred.

[0015] In addition, if the vibration pickup terminal 16 adopts a spring pin structure or a spring terminal structure in which a spring (not shown) is housed in the hollow of the shaft 162, the upper end of the spring is connected to the foot 161, and the lower end of the spring is connected to the front end 164, the length of the vibration pickup terminal 16 can be automatically adjusted, which is preferred.

[0016] If the total length of the vibration pickup terminal 16 in the vertical direction is formed to be a specified length (for example, several millimeters) longer than the total length of the shell 13 in the vertical direction, the metal plate 11, the vibration pickup terminal 16 and the plate 9 can be maintained in a state where pressure is always applied between the metal plate 11, the vibration pickup terminal 16 and the plate 9, thereby improving the sensitivity to sound waves propagating in the plate 9, which is preferred.

[0017] For example, in a case where the reception room and the waiting room of a hospital are separated by an acrylic resin plate or the like, by attaching the sound receiving device 1 of this embodiment to the acrylic resin plate on the reception room side (first space), it is possible to receive the sound generated in the waiting room (second space) with high accuracy and reproduce it using the speaker provided on the reception room side, so that people in the reception room and people in the waiting room can talk and communicate. For example, the same effect can be achieved in a case where the front seat and the rear seat (or the driver's seat and the passenger seat) of a taxi are separated by an acrylic resin plate or the like.

[0018] For another example, by attaching the sound receiving device 1 of this embodiment to the window glass inside the car (first space), the sound generated outside the car (second space) can be received with high precision and reproduced using the speakers installed inside the car, so that people inside the car and people outside the car can talk and communicate.

Claims

1. A sound receiving device, which is located in a first space and receives sound generated in a second space separated from the first space by a prescribed plate, characterized in that: The sound receiving device comprises: Metal sheets; a piezoelectric element fixed to the upper surface of the metal plate; A shell, which is in the shape of a cylinder with an open upper surface and a lower surface, and whose upper end surface is bonded to the lower surface of the metal plate and whose lower end surface is bonded to the plate; a vibration pickup terminal, which is accommodated in the housing and includes a foot portion bonded to the lower surface of the metal plate, a hollow shaft portion extending downward from the foot portion, and a front end portion formed at the front end in the lower direction of the shaft portion and in contact with the plate when the housing is bonded to the plate, The vibration pickup terminal has a spring pin structure in which a spring is accommodated in the hollow of the shaft portion, the upper end of the spring is connected to the leg portion, and the lower end of the spring is connected to the front end portion.

2. The sound receiving device according to claim 1, characterized in that: The total length of the vibration pickup terminal in the vertical direction is formed to be longer than the total length of the housing in the vertical direction.

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