Patent Description:
An array microphone system include a plurality of microphones, a screen and a protection film. The plurality of microphones are mounted on a substrate.

The screen is arranged on a front surface side of the substrate. The screen is a surface exposed to outside when the array microphone system is installed.

The protection film protects the plurality of microphones and the substrate from outside, and is attached to a back surface of the screen.

In the previously discussed array microphone system, when the screen is repainted, the protection film needs to be removed from the screen, and after repainting, the protection film needs to be attached to the screen again. Therefore, work of repainting the screen is complicated.

On the other hand, if the protection film is not arranged, protection performance of the plurality of microphones will be reduced. Attention is drawn to document <CIT> which relates a microphone assembly comprising an array microphone and a housing configured to support the array microphone and sized and shaped to be mountable in a drop ceiling in place of at least one of a plurality of ceiling tiles included in the drop ceiling. A front face of the housing includes a sound-permeable screen having a size and shape that is substantially similar to the at least one of the plurality of ceiling tiles. Or an array microphone system comprising a plurality of microphones arranged, on a substrate, in a number of concentric, nested rings of varying sizes around a central point of the substrate. Each ring comprises a subset of the plurality of microphones positioned at predetermined intervals along a circumference of the ring. Document <CIT> relates to a variable directional microphone assembly and a method of manufacturing the variable directional microphone assembly. The variable directional microphone assembly includes a substrate, a semiconductor integrated circuit device, two microphone devices, a microphone body, and a case. Document <CIT> relates to a microphone boot for a portable electronic device and a portable electronic device having such a microphone boot. There is provided a portable electronic device, comprising: a printed circuit board (PCB); a microphone attached to the PCB and defining an aperture therein; a frame enclosing the microphone and PCB and defining an opening therein; a cap attached to the frame and defining an aperture therein; and a microphone boot received in the opening in the frame and defining an acoustic channel between the aperture in the microphone and the aperture in the cap. Attention is also drawn to document <CIT> which relates to a mobile electronic device which includes: a housing; an acoustic-component contained in the housing; a sound hole formed in the housing, the sound hole being configured to allow communication between an inside and an outside of the housing; a non-breathable waterproof film disposed inside the housing, the waterproof film being configured to cover the sound hole; a compressible member compressed by being pressed against the housing during assembly of the acoustic-component to the housing, the compressible member being configured to form an acoustic-component chamber together with at least the waterproof film, the acoustic-component chamber being configured to hermetically seal the acoustic-component; and an opening configured to allow communication between an inside and an outside of the acoustic-component chamber within the housing, the opening being configured to allow air in the acoustic-component chamber to escape to the outside before the opening is closed in the process of compressing the compressible member. Finally, attention is drawn to document <CIT> which relates to MEMS microphone packages and fabrication methods thereof. A MEMS microphone package includes a casing with a conductive part disposed over a substrate, to enclose a cavity. A MEMS acoustic sensing element and an IC chip are disposed inside the cavity. An opening with an acoustic passage connects the cavity to an ambient space. A first ground pad is disposed on a backside of the substrate connecting to the conductive part of the casing through a via hole of the substrate. A second ground pad is disposed on the backside of the substrate connecting to the MEMS acoustic sensing element or the IC chip through an interconnection of the substrate, wherein the first ground pad and the second ground pad are isolated from each other.

This disclosure provides a microphone device capable of easily repainting a front panel such as a screen without reducing protection performance of a plurality of microphones.

The invention is defined by the appended independent claims <NUM> and <NUM>. Further embodiments of the invention are defined by the appended dependent claims. An inventive a microphone device includes a substrate, a plurality of microphones arranged on the substrate, a front panel configured to cover the substrate, and a dustproof member arranged so as to overlap the plurality of microphones in a plan view from a front panel side, and provided on a member different from the front panel.

The inventive microphone device can easily repaint the front panel such as a screen while protecting the plurality of microphones. Other objects, advantages and novel features of the embodiments of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings, in which:.

<FIG> is an exploded perspective view of a microphone device. <FIG> is a plan view of the microphone device. <FIG> is a side view of the microphone device, <FIG> is a side view of the microphone device without a front panel, and <FIG> is a side sectional view of the microphone device without the front panel. <FIG> is an enlarged side sectional view of a part of the microphone device. In <FIG>, some reference numerals are omitted for the sake of clarity of illustration. In <FIG>, an internal structure of the microphone device is schematically described for the sake of clarity of illustration.

As shown in <FIG>, <FIG>, <FIG>, a microphone device <NUM> includes a front panel <NUM>, a protection member <NUM>, a substrate <NUM>, a plurality of microphones <NUM>, a plurality of sound insulation walls <NUM>, a plurality of dustproof members <NUM>, and a rear panel <NUM>.

The front panel <NUM> has a box shape having a recess <NUM>. The front panel <NUM> has, for example, a mesh structure. The front panel <NUM> is not limited to the mesh structure as long as the front panel <NUM> has a structure that allows sound to pass therethrough (a structure having sound permeability).

The protection member <NUM> has a box shape having a recess <NUM>. The protection member <NUM> is formed of, for example, a plate material having rigidity such as a metal plate. More specifically, the protection member <NUM> includes a main plate <NUM> and a plurality of side plates <NUM>. The plurality of side plates <NUM> are arranged along an outer edge of the main plate <NUM> and are connected to the main plate <NUM>. At this time, the plurality of side plates <NUM> are connected so as to be orthogonal to the main plate <NUM>. Accordingly, the protection member <NUM> has the recess <NUM>. The main plate <NUM> has a plurality of holes <NUM>. The plurality of holes <NUM> penetrate the main plate <NUM> in a thickness direction.

The substrate <NUM> includes a first surface <NUM> and a second surface <NUM> that face each other. The substrate <NUM> includes, for example, a base material of an insulating resin and a conductor pattern formed on the base material. As shown in <FIG> and <FIG>, the substrate <NUM> has a plurality of holes <NUM>. The plurality of holes <NUM> penetrate the substrate <NUM> in the thickness direction.

The plurality of microphones <NUM> are, for example, MEMS microphones. The plurality of microphones <NUM> each include, for example, a housing having a sound receiving surface, and the sound receiving surface has a sound receiving hole.

<FIG> is a plan view and a side view of the sound insulation wall. As shown in <FIG>, the sound insulation wall <NUM> has a cylindrical shape and has a through hole <NUM>. A surface where the through hole <NUM> is open is an end surface of the sound insulation wall <NUM>. The sound insulation wall <NUM> is formed of an elastic member, and is formed of, for example, urethane foam, rubber, elastic resin or the like. The cylindrical wall has a predetermined thickness.

Accordingly, the sound insulation wall <NUM> prevents sound leakage in a direction orthogonal to an axial direction of the cylindrical shape. That is, the sound insulation wall <NUM> prevents sound propagating in an inner space from leaking to an outer space through the cylindrical wall. On the contrary, the sound insulation wall <NUM> prevents sound in the outer space from leaking to the inner space through the cylindrical wall. The sound insulation wall <NUM> is not limited to the cylindrical shape, and may have a tubular shape. That is, the sound insulation wall <NUM> may be a polygonal tube having a base material such as a triangular prism or a quadrangular prism.

<FIG> is a plan view and a side view of the dustproof member. The plurality of dustproof members <NUM> each have a sheet shape. The plurality of dustproof members <NUM> are formed of, for example, non-woven fabrics. The plurality of dustproof members <NUM> have sound permeability and prevent passage of substances that adversely affect the microphones <NUM>, such as dust and dirt.

The rear panel <NUM> is a plate having a front surface <NUM> and a back surface <NUM> facing each other and having a predetermined rigidity. The rear panel <NUM> is, for example, a metal plate.

Components of the microphone device <NUM> configured as described above are arranged as shown in <FIG>, <FIG>, <FIG> and <FIG>.

The substrate <NUM> is fixed to the rear panel <NUM>. The second surface <NUM> of the substrate <NUM> and the front surface <NUM> of the rear panel <NUM> face each other.

The plurality of microphones <NUM> are arranged on the second surface <NUM> of the substrate <NUM>. The plurality of microphones <NUM> are connected to a conductor pattern formed on the substrate <NUM>. The plurality of microphones <NUM> are arranged such that sound receiving surfaces face the substrate <NUM>. The plurality of microphones <NUM> are arranged such that sound receiving holes overlap the holes <NUM> of the substrate <NUM> in a plan view of the microphone device <NUM>. The plan view of the microphone device <NUM> refers to a state where the rear panel <NUM>, the substrate <NUM>, the protection member <NUM> and the front panel <NUM> are viewed from a front panel side when the components of the microphone device <NUM> are assembled. Hereinafter, the plan view of the microphone device <NUM> means the above state and is simply described as "plan view".

An opening diameter of each of the plurality of holes <NUM> is determined according to a specification of each of the plurality of microphones <NUM>, for example, a diameter of the sound receiving hole. For example, the opening diameter of each of the plurality of holes <NUM> may be approximately equal to the opening diameter of the sound receiving hole of each of the plurality of microphones <NUM>. Accordingly, the microphone device <NUM> can prevent the hole <NUM> of the substrate <NUM> from being unnecessarily large, and can prevent the sound receiving hole from being unnecessarily closed due to positional deviation when the plurality of microphones <NUM> are mounted on the substrate <NUM>.

The plurality of sound insulation walls <NUM> are arranged on the first surface <NUM> of the substrate <NUM>. One end surface of each of the plurality of sound insulation walls <NUM> is in contact with the first surface <NUM> of the substrate <NUM>. The plurality of sound insulation walls <NUM> are respectively arranged in the plurality of holes <NUM> of the substrate <NUM>. More specifically, each one of the plurality of sound insulation walls <NUM> is arranged corresponding to each one of the plurality of holes <NUM>. At this time, the central opening of each of the plurality of sound insulation walls <NUM> overlaps the hole <NUM> of the substrate <NUM> in the plan view. That is, the plurality of sound insulation walls <NUM> are arranged so as to respectively surround the plurality of microphones <NUM> in the plan view.

Preferably, one end surface of each of the plurality of sound insulation walls <NUM> is bonded and joined to the first surface <NUM> of the substrate <NUM> by an adhesive material or the like.

An opening diameter of each of the plurality of sound insulation walls <NUM> is larger than the opening diameter of the hole <NUM> of the substrate <NUM>. Accordingly, the microphone device <NUM> can prevent the holes <NUM> and wall portions of the plurality of sound insulation walls <NUM> from overlapping each other due to an error in arranging the plurality of sound insulation walls <NUM> on the substrate <NUM>.

<FIG> is a plan view and a side view of a state where the sound insulation wall and the dustproof member are combined. As shown in <FIG>, each of the plurality of dustproof members <NUM> is attached to the other end surface of each of the plurality of sound insulation walls <NUM>. At this time, each of the plurality of dustproof members <NUM> is attached so as to close the central opening of each of the plurality of sound insulation walls <NUM>. Each one of the plurality of dustproof members <NUM> is arranged corresponding to each one of the plurality of sound insulation walls <NUM>. Preferably, the plurality of dustproof members <NUM> are respectively bonded and joined to the plurality of sound insulation walls <NUM> by an adhesive material or the like.

An outer diameter of each of the plurality of dustproof members <NUM> may be equal to or larger than an inner diameter of the sound insulation wall <NUM> and may be approximately equal to an outer diameter of the sound insulation wall <NUM>. Accordingly, the central opening of the sound insulation wall <NUM> can be more reliably closed by the dustproof member <NUM> without excessively increasing a shape of the dustproof member <NUM>.

The protection member <NUM> is fixed to the rear panel <NUM> so as to overlap the substrate <NUM> in the plan view. At this time, the protection member <NUM> is fixed to the rear panel <NUM> such that the substrate <NUM> on which the plurality of microphones <NUM> are mounted, the plurality of sound insulation walls <NUM>, and the plurality of dustproof members <NUM> are accommodated in the recess <NUM>. The protection member <NUM> is arranged such that each of the plurality of holes <NUM> overlap the central opening of each of the plurality of sound insulation walls <NUM> in the plan view.

An opening diameter of each of the plurality of holes <NUM> is preferably larger than the inner diameter of each of the plurality of sound insulation walls <NUM> and smaller than an outer shape. Accordingly, the microphone device <NUM> can prevent the hole <NUM> from overlapping the central opening of the sound insulation wall <NUM> due to an installation error or the like of the plurality of sound insulation walls <NUM>, and can prevent occurrence of a portion where the hole <NUM> does not overlap the sound insulation wall <NUM> and the dustproof member <NUM>.

The front panel <NUM> has the sound permeability (acoustic transparency). The front panel <NUM> is realized by, for example, the mesh structure of metal, plastic or the like, a film having the sound permeability, or the like. The mesh structure also includes a so-called grill structure. The front panel <NUM> is fixed to the rear panel <NUM> by being arranged so as to overlap the protection member <NUM>, in other words, so as to overlap the substrate <NUM> on which the plurality of microphones <NUM> are mounted, the plurality of sound insulation walls <NUM>, and the plurality of dustproof members <NUM>, in the plan view.

The microphone device <NUM> has a configuration described above to obtain the following advantageous effects.

Sound from outside of the microphone device <NUM> passes through the front panel <NUM>, passes through the plurality of holes <NUM> of the protection member <NUM>, passes through the plurality of dustproof members <NUM> and central openings of the plurality of sound insulation walls <NUM>, passes through the plurality of holes <NUM> of the substrate <NUM>, and is collected by the plurality of microphones <NUM>. Accordingly, the microphone device <NUM> can collect the external sound by the plurality of microphones <NUM>.

The dust, dirt and the like from the outside of the microphone device <NUM> are adsorbed by the plurality of dustproof members <NUM>. Accordingly, the microphone device <NUM> can prevent the dust, dirt and the like from reaching the plurality of microphones <NUM>.

The plurality of dustproof members <NUM> are not attached to the front panel <NUM>. Therefore, the plurality of dustproof members <NUM> need not to be removed from the front panel <NUM> when the front panel <NUM> is repainted or the like. Accordingly, a worker or a user can easily repaint the front panel <NUM>.

The plurality of dustproof members <NUM> are arranged between the protection member <NUM> and the plurality of sound insulation walls <NUM>. That is, the plurality of dustproof members <NUM> are protected by the protection member <NUM>. Therefore, when the front panel <NUM> is replaced, the worker or the user is prevented from coming into contact with the plurality of dustproof members <NUM>, and the plurality of dustproof members <NUM> are prevented from being damaged.

Each of the plurality of sound insulation walls <NUM> is provided for each of the plurality of microphones <NUM>. Accordingly, the microphone device <NUM> can prevent acoustic coupling of the plurality of microphones <NUM>.

Particularly, in an aspect including the protection member <NUM>, a substantially closed space is formed between the protection member <NUM> and the substrate <NUM>. In such a case, if there are no plurality of sound insulation walls <NUM>, the acoustic coupling is likely to occur due to the substantially closed space.

However, in the microphone device <NUM>, each of the plurality of sound insulation walls <NUM> is arranged for each of the plurality of microphones <NUM>. One end surface of each of the plurality of sound insulation walls <NUM> is in contact with the first surface <NUM> of the substrate <NUM>, and the other end surface thereof abuts against the protection member <NUM> via each of the plurality of dustproof members <NUM>. Accordingly, an acoustically independent space (a sound propagation path) can be formed for each of the plurality of microphones <NUM> in the space between the protection member <NUM> and the substrate <NUM>. As a result, the microphone device <NUM> can more effectively prevent the acoustic coupling of the plurality of microphones <NUM>.

The protection member <NUM> is preferably installed so as to press the plurality of sound insulation walls <NUM> against the substrate <NUM>. In this case, if the plurality of sound insulation walls <NUM> are elastic members, a height of each of the plurality of sound insulation walls <NUM> is lower when the protection member <NUM> is arranged than when the protection member <NUM> is not arranged. In other words, a distance between the end surface of the sound insulation wall <NUM> on a protection member <NUM> side and the end surface on a substrate <NUM> side is short. Since the plurality of sound insulation walls <NUM> are elastic members, a gap between the plurality of sound insulation walls <NUM> and the first surface <NUM> of the substrate <NUM> is prevented by the pressing. Similarly, a gap between the protection member <NUM> and the plurality of dustproof members <NUM> is prevented. Therefore, the sound leakage in a direction parallel to the first surface <NUM> of the substrate <NUM> is further prevented, and the microphone device <NUM> can more effectively prevent the acoustic coupling of the plurality of microphones <NUM>. For this reason, the plurality of sound insulation walls <NUM> are preferably elastic members, but may not be elastic members as long as the plurality of sound insulation walls <NUM> are formed of a material having sound insulation performance. The plurality of sound insulation walls <NUM> may have elastic members in vicinity of both end surfaces, and may have other members therebetween.

The plurality of microphones <NUM> are MEMS microphones. Accordingly, the microphone device <NUM> is thin. The plurality of microphones <NUM> can be easily mounted on the substrate <NUM>, and for a configuration including many microphones <NUM> such as the microphone device <NUM>, the microphone device <NUM> can be manufactured more easily than using microphones having another structures. For this reason, the plurality of microphones <NUM> are preferably MEMS microphones, but the plurality of microphones <NUM> may be different from the MEMS microphones.

Although not described in detail in the above description, the plurality of microphones <NUM> are randomly arranged. The random arrangement refers to, for example, an arrangement different from an arrangement in which the plurality of microphones <NUM> are arranged in a straight line or an arrangement in which the plurality of microphones <NUM> are arranged on a circumference having a certain diameter. In contrast to such a configuration, the microphone device <NUM> individually includes the plurality of sound insulation walls <NUM> and the plurality of dustproof members <NUM> respectively for the plurality of microphones <NUM>. Therefore, the microphone device <NUM> can reliably arrange the plurality of sound insulation walls <NUM> and the plurality of dustproof members <NUM> respectively for the plurality of microphones <NUM>, regardless of an arrangement pattern of the plurality of microphones <NUM>. Shapes of the plurality of sound insulation walls <NUM> and the plurality of dustproof members <NUM> can be unified, and the plurality of sound insulation walls <NUM> and the plurality of dustproof members <NUM> can be easily manufactured and attached.

The arrangement of the plurality of microphones <NUM> is not random, and may be spiral, linear or polygonal. A spiral arrangement, a linear arrangement and a polygonal arrangement may be singular, plural, or a combination of many types.

The plurality of microphones <NUM> are, for example, an array microphone that forms a sound collection beam. When the plurality of microphones <NUM> are used as the array microphone, the acoustic coupling of the plurality of microphones <NUM> is prevented as described above, so that a desired sound collection beam can be formed more accurately. The plurality of microphones <NUM> may not constitute the array microphone.

The microphone device <NUM> having such a configuration is used, for example, as follows. <FIG> is a perspective view showing an example of an installation mode of the microphone device.

As shown in <FIG>, the microphone device <NUM> is installed in a room <NUM> for a sound collection target. At this time, the microphone device <NUM> is installed on a ceiling <NUM> of the room <NUM>. More specifically, the microphone device <NUM> is installed on the ceiling <NUM> such that the front panel <NUM> faces a floor <NUM> of the room <NUM>. That is, the microphone device <NUM> is used as a so-called sealing microphone. A shape of the front panel <NUM> in the plan view is preferably a shape that can be replaced with a panel of the ceiling <NUM>. For example, the shape may be adapted to a shape typically determined in countries such as the United States and Europe. This facilitates work of installing the microphone device <NUM> on the ceiling <NUM>.

In such a usage mode, the user may repaint a color of the front panel <NUM> according to a design of the room <NUM>. In such a case, the front panel <NUM> is removed, but the worker or the user can easily repaint or replace the front panel <NUM> by providing the configuration of the microphone device <NUM> as described above.

The configuration described above is an example, and for example, the microphone device may have a configuration shown in the following example. <FIG> are partial enlarged side views showing the configuration of a derivative example of the microphone device.

As shown in <FIG>, in a microphone device 10A, a positional relationship between the plurality of sound insulation walls <NUM> and the plurality of dustproof members <NUM> is opposite to that of the microphone device <NUM>. Other configurations of the microphone device 10A are the same as those of the microphone device <NUM>, and description thereof will be omitted. In the microphone device 10A, the plurality of dustproof members <NUM> are arranged between the plurality of sound insulation walls <NUM> and the first surface <NUM> of the substrate <NUM>.

As shown in <FIG>, a microphone device 10B is different from the microphone device <NUM> in that the dustproof member <NUM> common to the plurality of sound insulation walls <NUM> is used. Other configurations of the microphone device 10B are the same as those of the microphone device <NUM>, and description thereof will be omitted. In the microphone device 10B, the dustproof member <NUM> is arranged so as to overlap the plurality of sound insulation walls <NUM>.

As shown in <FIG>, a microphone device 10C is different from the microphone device <NUM> in that the plurality of dustproof members <NUM> are attached to the protection member <NUM>. Other configurations of the microphone device 10C are the same as those of the microphone device <NUM>, and description thereof will be omitted. In the microphone device 10C, the plurality of dustproof members <NUM> are arranged on a surface of the protection member <NUM> opposite to a contact surface thereof with the plurality of sound insulation walls <NUM>. The plurality of dustproof members <NUM> are attached to the protection member <NUM> with, for example, an adhesive material.

In this way, in the microphone device according to the present disclosure, the dustproof member <NUM> may be attached to a member (a component of the microphone device) different from the front panel <NUM>.

In the above description, the protection member <NUM> can be omitted except for the configuration in <FIG>. The plurality of sound insulation walls <NUM> can be omitted in that the worker or the user can easily repaint or replace the front panel <NUM>.

Claim 1:
A microphone device (<NUM>) comprising:
a substrate (<NUM>);
a plurality of microphones (<NUM>) arranged on the substrate (<NUM>);
a front panel (<NUM>) configured to be installed on a ceiling (<NUM>), and to have a shape that can be replaced with a panel of the ceiling (<NUM>), and configured to cover the substrate (<NUM>);
a plurality of dustproof members (<NUM>) each respectively arranged so as to respectively overlap the plurality of microphones (<NUM>) in a plan view of the microphone device viewed from a front panel side, and provided on a member different from the front panel (<NUM>);
a plurality of sound insulation walls (<NUM>) each having a tubular shape and respectively arranged between the plurality of microphones (<NUM>) and the front panel so as to not overlap the plurality of microphones (<NUM>) in the plan view, and
a plate-shaped protection member (<NUM>) arranged between the front panel (<NUM>) and the substrate (<NUM>), and having a plurality of holes (<NUM>) located at a central opening of each of the plurality of sound insulation walls (<NUM>),
wherein each one of the plurality of the dustproof members (<NUM>) is arranged corresponding to each one of end surfaces of the plurality of sound insulation walls (<NUM>), and
wherein one end surface of each of the plurality of sound insulation walls (<NUM>) which is arranged for each of the plurality of microphones (<NUM>) is in contact with a first surface of the substrate (<NUM>), and another end surface thereof abuts against the protection member (<NUM>) via each of the plurality of dustproof members (<NUM>), and thereby a recess (<NUM>) is formed with the protection member (<NUM>), the plurality of sound insulation walls (<NUM>) and the substrate (<NUM>).