Patent Description:
There have conventionally been proposed covering members made up of a saran net or the like and configured to be provided on a sound radiation side of a sound radiation apparatus such as a speaker apparatus or the like provided in an acoustic device such as an electronic musical instrument to cover a sound radiation port thereof. For example, <CIT> (<CIT>) discloses a sound radiation structure in which a covering member, which can transmit sound, is fixed to a sound radiation body. In this sound radiation structure, a groove portion is provided in the sound radiation body so that a fixing member is pushed thereinto. With the sound radiation body covered with the covering member, a portion of the covering member is held between the groove portion and the fixing member and is then pushed into the groove portion to thereby fix the covering member strongly to the sound radiation body. <CIT> discloses a cover for sound radiation apparatus for a speaker box having several layers protecting the speaker unit and providing a mesh plate fixed above the cover holes. Several layers of bounding elements are provided, with the second bounding layer <NUM> having a thickness larger than the first layer <NUM>.

According to an aspect of the present disclosure, there is provided a sound radiation apparatus including a sound radiation unit, a first member having an opening area which is provided in such a manner as to be superposed above at least a sound radiation port of the sound radiation unit and which is made up of multiple opening portions at a location which is superposed above the sound radiation port, a second member provided to be superposed on a side of the first member which is opposite to a side thereof which faces the sound radiation unit in such a manner as to surround the opening area of the first member, and a covering member configured to cover the first member and a side of the second member which is opposite to a side thereof which faces the sound radiation unit and bonded to the second member, wherein the second member and the covering member are bonded together at an area on the second member which excludes a portion surrounding a circumference of the opening area of the first member with a first adhesive and at an area on the second member which surrounds the circumference of the opening area of the first member with a second adhesive having a higher bonding strength than a bonding strength of the first adhesive.

According to another aspect of the present disclosure, there is provided an electronic musical instrument comprising the above-described sound radiation apparatus.

According to yet another aspect of the present disclosure, there is provided a sound radiation apparatus fabrication method including a first disposition step of disposing a first member having an opening area made up of multiple opening portions in such a manner that the opening area is superposed above a sound radiation port of a sound radiation unit, a second disposition step of disposing a second member to be disposed on a side of the first member which is opposite to a side thereof which faces the sound radiation unit in such a manner as to surround the opening area of the first member, and a bonding step of bonding a covering member to the second member in such a manner as to cover the first member and a side of the second member which is opposite to a side thereof which faces the sound radiation unit, wherein in the bonding step, the second member and the covering member are bonded together at an area on the second member which excludes a portion surrounding a circumference of the opening area of the first member with a first adhesive and an area on the second member which surrounds the circumference of the opening area of the first member with a second adhesive having a higher bonding strength than a bonding strength of the first adhesive.

Hereinafter, an application example of the present disclosure will be described based on drawings. As shown in <FIG>, an electronic keyboard instrument <NUM> (an electronic musical instrument) which is an acoustic device comprises a keyboard <NUM> consisting of sixty-one keys and an instrument case <NUM>. An operating section <NUM> having an adjustment knob <NUM> is provided at the upper surface <NUM> of the electronic musical instrument <NUM>. As shown in <FIG>, the back side of the instrument case <NUM> is formed as a sound radiation apparatus having a plurality of speakers <NUM>.

Referring to <FIG>, an embodiment or application example of the present disclosure will be described. <FIG> is an overall perspective view showing a main part of a speaker apparatus (a sound radiation apparatus) <NUM> according to the application example of the present disclosure. As shown in <FIG>, the speaker apparatus <NUM> includes four speakers (sound radiation units) <NUM>, which are disposed in such a manner that sound radiation sides are oriented substantially to a front side (a nearer side in <FIG>). In the following description, an upside of the speaker apparatus <NUM> in <FIG> and <FIG> is referred to as an upper side, and an opposite side is referred to a lower side. A right side of the speaker apparatus <NUM> in <FIG> and <FIG> is referred to as a right side, and an opposite side is referred to as a left side. A nearer side of the speaker apparatus <NUM> (a sound radiation side of each speaker <NUM>) is referred to as a front side (a front side), and an opposite side is referred to as a rear side (a back side).

The speaker apparatus <NUM> includes, on a front side thereof, a first cover (a first member) <NUM>, a second cover (a second member) <NUM>, which is disposed at a front of the first cover <NUM>, the four speakers <NUM>, and a saran net <NUM>, which is configured to cover the first cover <NUM> and a front side of the second cover <NUM> (refer to <FIG> and <FIG>). The speaker apparatus <NUM> has an external appearance of a horizontally elongated rectangular parallelepiped shape and the portion excluding a front side thereof is made up of a housing which is the instrument case <NUM> of the electronic keyboard instrument <NUM>(an electronic musical instrument). A control circuit board or the like, not shown, for controlling the speaker apparatus <NUM> is disposed in an interior portion of the housing. Here, only a portion (an upper panel <NUM>) of the housing, which makes up the external appearance of the speaker apparatus <NUM>, is shown in <FIG>. The other portions of the housing of the speaker apparatus <NUM> are made up of the instrument case <NUM> constituted by general panel members or the like which then make up a rear side, both left and right sides, and a lower side of the speaker apparatus <NUM>.

The upper panel <NUM>, which makes up a part of the housing and which has a horizontally elongated rectangular plate shape, is provided on an upper side of the speaker apparatus <NUM>. The four speakers <NUM> each have a sound radiation port 10a, which defines a horizontally elongated oval shape as viewed from a front side thereof, and two speakers <NUM> are disposed side by side at each of left- and right-side portions of the speaker apparatus <NUM>. On the front side of the speaker apparatus <NUM>, a power supply switch <NUM> for switching on and off a power supply for the two speakers <NUM> disposed on the left-side portion of the speaker apparatus <NUM> is provided at a right upper portion relative to the relevant two speakers <NUM>, and a power supply switch <NUM> for switching on and off a power supply for the two speakers <NUM> disposed on the right-side portion of the speaker apparatus <NUM> is provided at a left upper portion relative to the relevant two speakers <NUM>. In addition, a terminal panel <NUM>, into which various types of terminals are inserted, is provided at a centrally lower side on the front side of the speaker apparatus <NUM>.

The four speakers <NUM> provided in the speaker apparatus <NUM> have the same configuration. As shown in <FIG>, each speaker <NUM> is a general cone-type speaker and is provided at a front portion of the speaker apparatus <NUM> in such a state that the sound radiation port 10a is oriented to the front side. Each speaker <NUM> has a magnet portion <NUM> disposed at a rear side, a coil portion <NUM> disposed at a central portion lying inwards of the magnet portion <NUM>, a cap portion <NUM> disposed at a central portion on the front side, a substantially circular truncated cone-shaped vibration plate <NUM> which expands radially outwards as it extends to the front, a frame portion <NUM> which supports an external side of the vibration plate <NUM>, and the like. An outer circumferential edge portion of the vibration plate <NUM> is formed into an edge portion 18a. In each speaker <NUM>, a sound radiation center C is positioned on an upper portion of the cap portion <NUM>.

As shown in <FIG>, the first cover <NUM> is a horizontally elongated rectangular plate-shaped member made of a synthetic resin and is disposed in such a manner as to cover the front sides of the two adjacent speakers <NUM>, which are disposed side by side at each of the right- and left-side portions of the speaker apparatus <NUM>. That is, the speaker apparatus <NUM> includes two first covers <NUM>. Each first cover <NUM> has two mesh portions <NUM>, which are provided in such a manner as to be superposed above the corresponding sound radiation ports 10a of the two speakers <NUM>, a frame-shaped portion <NUM> provided in such a manner as to surround a circumference of each of the mesh portions <NUM> in a frame-like fashion, and a plate-shaped portion <NUM> of a horizontally elongated plate-like shape provided outside the frame-shaped portion <NUM>.

The plate-shaped portion <NUM> is attached to the upper panel <NUM>, the control circuit board in an interior portion of the speaker apparatus <NUM>, and the like with machine screws or the like in such a state that both plate surfaces thereof are oriented in a front-rear direction. The frame-shaped portion <NUM> protrudes forwards from a front surface of the plate-shaped portion <NUM> in a step-like fashion and is provided in such a manner as to surround a circumference of each of the mesh portions <NUM> within a horizontally elongated substantially regular octagonal shape.

Each mesh portion <NUM> is provided in such a manner as to protrude forwards slightly from a front surface of the frame-shaped portion <NUM>, and an outer edge portion 52a of the mesh portion <NUM> defines a horizontally elongated substantially oval shape similar to that of the sound radiation port 10a of each speaker <NUM>. The first cover <NUM> is disposed in such a manner that the outer edge portion 52a of the mesh portion <NUM> surrounds the edge portion 18a of the vibration plate <NUM> of the speaker <NUM>. Each mesh portion <NUM> constitutes an opening area <NUM> which is made up of multiple opening portions which are defined by a first beam 52b, which is laid out from the outer edge portion 52a into a so-called honeycomb structure of a network of substantially hexagonal meshes, and a second beam 52c, which is laid out from the outer edge portion 52a to extend in vertical and horizontal directions. As shown in <FIG> and the like, the opening area <NUM> includes an opening portion 53a which is provided in a position which is superposed above the sound radiation center C of the speaker <NUM>.

Here, as shown in <FIG> and <FIG>, a thin vertically elongated substantially rectangular cushion member (a buffer member) <NUM>, whose shape follows the first beam 52b and the second beam 52c, is disposed on a front surface of a substantially central portion of the opening area <NUM> (between the first cover <NUM> and the saran net <NUM>, which will be described later). That is, the cushion member <NUM> is disposed in such a manner as to lie along a non-opening portion of the opening area <NUM> and has, at a central portion thereof, a bent beam-shaped portion (a beam-shaped portion) 80a, which is bent substantially into a collapsed V-shape along the non-opening portion of the opening area <NUM> at the sound radiation center C of the speaker <NUM>. As a result, the cushion member <NUM> is disposed in the position which is superposed above the sound radiation center C of the speaker <NUM>. The cushion member <NUM> is formed of a foamed urethane, elastomer, silicone, or the like, and has a thickness of, for example, <NUM>. The cushion member <NUM> is affixed to the first beam 52b and the second beam 52c with an adhesive or the like. Thus, the cushion member <NUM> can increase an in-plane strength in a plan view by incorporating the bent beam-shaped portion 80a described above, thereby making it possible to improve the working efficiency in affixing the cushion member <NUM> to the first cover <NUM>.

As shown in <FIG> and <FIG>, the second cover <NUM> is made of a synthetic resin, constitutes a horizontally elongated rectangular plate-shaped member whose front surface is made into a flat plane, and is disposed in such a manner as to cover the front side of the speaker apparatus <NUM> excluding portions corresponding to the power supply switches <NUM>, the terminal panel <NUM>, and the sound radiation ports 10a of the four speakers <NUM>. Then, the second cover <NUM> has sound radiation port opening portions 60a formed in positions which are superposed above the sound radiation ports 10a of the four speakers <NUM> in such a manner as to face individually the corresponding sound radiation ports. In other words, the second cover <NUM> is provided to surround individually the opening areas <NUM> in the first covers <NUM> in such a manner as to be superposed on sides of the first cover <NUM> which are opposite to the sides thereof which face the speakers <NUM>. As a result, sound radiated from each speaker <NUM> is prevented from being interrupted by the second cover <NUM>.

As shown in <FIG>, specifically speaking, the second cover <NUM> is disposed so that the second cover <NUM> is brought into abutment with front surfaces of the plate-shaped portion <NUM> and the frame-shaped portion <NUM> of the first cover <NUM> and that the sound radiation port opening portions 60a thereof lie in the vicinity of the outer edge portions 52a of the mesh portions <NUM> of the first cover <NUM>. With the second cover <NUM> disposed on the front surface side of the first cover <NUM>, a front surface of the second cover <NUM> is positioned further forwards (further upwards in <FIG>) than the mesh portions <NUM> of the first cover <NUM>.

The saran net <NUM> is formed of chemical fibers of, for example, polyester or the like, so that the saran net <NUM> constitutes a member whose transmission loss of sound radiated from each speaker <NUM> is small (a member having a superior sound transmission capability). The saran net <NUM> has a horizontally elongated rectangular shape and is one size larger than the second cover <NUM> as a whole. As shown in <FIG>, the saran net <NUM> is provided in such a manner as to be bonded to the front surface of the second cover <NUM>, which is formed into the flat plane, side surfaces of the second cover <NUM>, and a part of a rear surface of the second cover <NUM>, whereby the saran net <NUM> covers the front surface and side surfaces of the second cover <NUM> and the mesh portions <NUM> (the sound radiation ports 10a of the speakers <NUM>) of the first cover <NUM>. The saran net <NUM> and the mesh portions <NUM> of the first cover <NUM> are spaced apart from each other (over an area where the saran net <NUM> and the first cover <NUM> are superposed on each other) to thereby define a gap D1 of, for example, <NUM> therebetween. The saran net <NUM> and the cushion member <NUM> lie close to each other to thereby define a gap of, for example, <NUM> therebetween. Thus, as is described above, the saran net <NUM> is supported on a side thereof which faces the sound radiation ports 10a of the speakers <NUM> by the two members of the first cover <NUM> and the second cover <NUM>.

Next, referring to <FIG>, a bonding mode of bonding the saran net <NUM> to the second cover <NUM> will be described in detail. An area A1 on the front surface of the second cover <NUM> which excludes areas surrounding the sound radiation port opening portions 60a (portions which are superposed on the opening areas <NUM> in the first cover <NUM>) and the saran net <NUM> are bonded together with a first adhesive B1. The first adhesive B1 is, for example, an adhesive in the form of a solvent of a styrene-butadiene rubber family having a low viscosity. On the other hand, areas A2 on the front surface of the second member <NUM> which correspond to the areas surrounding the sound radiation port opening portions 60a (the portions which are superposed on the opening areas <NUM> in the first cover <NUM>) and the saran net <NUM> are bonded together with a second adhesive B2, which has a bonding strength higher than that of the adhesive B1. The second adhesive B2 is, for example, an adhesive in the form of a solvent of a chloroprene rubber family having a high viscosity. Here, the fact that an adhesive has a higher bonding strength means that one has to have more difficulty in separating things bonded together with the adhesive once it has set. States of the first adhesive B1 and the second adhesive B2 include states before and after the adhesives have set.

Since the areas A2 on the front surface of the second cover <NUM> which surround the sound radiation port opening portions 60a and the saran net <NUM> are bonded together with the adhesive B2 having the superior bonding strength in the way described above, portions of the saran net <NUM> which are superposed above the sound radiation port opening portions 60a, that is, areas A3 of the saran net <NUM> which are surrounded by the portions bonded with the second adhesive B2 are in such a state that a saran material is stretched due to tension exerted thereon. Here, the state in which the saran net <NUM> is stretched due to tension exerted thereon means a state in which almost no wrinkle or looseness is visible on the saran net <NUM>, which exhibits a large spring-back force (resilient restoration force) when the saran net <NUM> is depressed down.

Next, a fabrication method of the speaker apparatus <NUM> according to the present application example will be described. A known speaker apparatus fabrication method can be applied to a step of assembling the housing including the upper panel <NUM> and a step of assembling the control circuit board and the like into the speaker apparatus <NUM>, and hence, the description of those steps will be omitted here. In the present fabrication method, firstly, the first cover <NUM> is disposed in front of the speakers <NUM> in such a manner that the opening areas <NUM> in the first cover <NUM> are superposed above the sound radiation ports 10a of the speakers <NUM> and is then assembled to the housing of the speaker apparatus <NUM> (a first disposition step). Subsequently, the second cover <NUM> is disposed in front of the first cover <NUM> in such a manner as to surround the opening areas <NUM> of the first cover <NUM> (a second disposition step). That is, the second cover <NUM> is disposed in front of the first cover <NUM> in such a manner that the sound radiation port opening portions 60a of the second cover <NUM> are superposed above the opening areas <NUM> of the first cover <NUM> and is then assembled to the first cover <NUM>.

Next, the first adhesive B1 is sprayed on to the area A1 and the areas A2 (refer to <FIG>) using a spray device. Subsequently, the second adhesive B2, whose bonding strength is higher than that of the first adhesive B1, is applied to the areas A2 (refer to <FIG>) surrounding the sound radiation port opening portions 60a on the front surface of the second cover <NUM> using a brush or the like. Subsequently, the saran net <NUM> is bonded to the area A1 to which the first adhesive B1 is applied and the areas A2 to which the first adhesive B1 and the second adhesive B2 are applied, and the front sides of the first cover <NUM> and the second cover <NUM> are covered by the saran net <NUM> so bonded (a bonding step).

In bonding the saran net <NUM>, the saran net <NUM> is bonded to the second cover <NUM> in such a state that the portions of the saran net <NUM> which are superposed above the sound radiation port opening portions 60a, that is, the areas A3 (refer to <FIG>) surrounded by the portions which are bonded with the second adhesive B2 are stretched due to tension exerted thereto. The exertion of tension on to the saran net <NUM> can be executed, for example, by stretching the saran net <NUM> with a uniform force exerted from the circumferences of the areas A2 to which the second adhesive B2 is applied.

Here, in the case that only the second adhesive B2 having the high bonding strength is used, the working efficiency of the step of bonding the saran net <NUM> is deteriorated. The step of bonding the saran net <NUM> is not such a step that tension is exerted on the whole surface of the saran net <NUM> so as to bond the saran net <NUM> altogether at one time, but in an actual step of bonding the saran net <NUM>, tension is exerted manually on to portions of the saran net <NUM> a bit by a bit. In the case that the adhesive is erroneously applied to portions of the saran net <NUM> which are not desired to be bonded, in the event that the adhesive used is the second adhesive B2 having the high bonding strength, the resulting bonding effect will become too strong undesirably. On the other hand, in the case that only the first adhesive B1 having the low bonding strength is used, although large tension is required to prevent an occurrence of resonance in the saran net <NUM>, the required large tension cannot be secured only with the first adhesive B1 having the low bonding strength. Then, large tension can be exerted on to the saran net <NUM> while securing the working efficiency of the bonding step of the saran net <NUM> by using the two types of adhesives in the way described above.

As described heretofore, with the speaker apparatus <NUM> according to the present application example, the first cover <NUM> is provided in such a manner that the opening areas <NUM> are superposed above the sound radiation ports 10a of the speakers <NUM>, the second cover <NUM> is provided on the side of the first cover <NUM> which is opposite to the side thereof which faces the speakers <NUM> in such a manner that the sound radiation port opening portions 60a are superposed above the opening areas <NUM>, and the saran net <NUM> is provided to cover the first cover <NUM> and the side (the front side) of the second cover <NUM> which is opposite to the side thereof which faces the speakers <NUM> while being bonded to the second cover <NUM>. As a result, the saran net <NUM> is supported on the side thereof which faces the sound radiation ports 10a of the speakers <NUM> by the two members of the first cover <NUM> and the second cover <NUM>. By adopting this configuration, the sufficient gap is secured between the sound radiation ports 10a of the speakers <NUM> and the opening areas <NUM> of the first cover <NUM>, and the saran net <NUM>.

Further, with the speaker apparatus <NUM> according to the present application example, the second cover <NUM> and the saran net <NUM> are bonded together with the first adhesive B1 at the area A1, and the second cover <NUM> and the saran net <NUM> are bonded together with the second adhesive B2, which has the higher bonding strength than that of the first adhesive B1, at the areas A2 on the front surface of the second cover <NUM> which surround the circumferences the sound radiation port opening portions 60a. By adopting this configuration, the large tension is exerted on the areas A3 which are surrounded by the portions bonded with the second adhesive B2, compared with the area A1 which is bonded with the first adhesive B1. Thus, with the speaker apparatus <NUM> according to the present application example, the large tension can be exerted on the saran net <NUM> while securing the sufficient gap between the sound radiation ports 10a of the speakers <NUM> and the saran net <NUM>, thereby making it possible to prevent or suppress the occurrence of resonance in the saran net <NUM>.

In addition, with the speaker apparatus <NUM>, the saran net <NUM> is bonded to the second cover <NUM> with the tension exerted on at least the areas A3 which are surrounded by the portions bonded with the second adhesive B2. As a result, the larger tension can be exerted on the saran net <NUM> at the areas A3, thereby making it possible to prevent or suppress the occurrence of resonance in the speaker apparatus <NUM> more effectively.

With the speaker apparatus <NUM>, the areas of the saran net <NUM> which are superposed above the opening areas <NUM> of the first cover <NUM> are spaced apart from the relevant opening areas <NUM>. As a result, the specific configuration to secure the sufficient gap between the opening areas <NUM> of the first cover <NUM> and the saran net <NUM> can be provided.

With the speaker apparatus <NUM>, the opening area <NUM> of the first member or the first cover <NUM> includes the opening portion 53a which is provided in the position which is superposed above the sound radiation center C of the speaker <NUM>. As a result, since sound radiated from the sound radiation center C where sound becomes largest in magnitude passes through this opening portion 53a, sound radiated from the speaker <NUM> can be prevented from being lost or interrupted by the first cover <NUM>.

With the speaker apparatus <NUM>, the cushion member <NUM> is provided to be disposed between the first cover <NUM> and the saran net <NUM> while being bonded to the first cover <NUM>. As a result, vibrations of the first cover <NUM> generated by sound radiated from the speakers <NUM> can be suppressed by the cushion member <NUM>, thereby making it possible to prevent or suppress the occurrence of resonance in the speaker apparatus <NUM> effectively.

In addition, with the speaker apparatus <NUM>, the cushion member <NUM> is bonded to the first cover <NUM> in such a manner as to lie along the non-opening portion of the opening area <NUM> of the first cover <NUM>. As a result, vibrations of the first cover <NUM> in association with sound radiated from the speakers <NUM> can be suppressed further by the cushion member <NUM>, thereby making it possible to prevent or suppress the occurrence of resonance in the speaker apparatus <NUM> more effectively.

With the speaker apparatus <NUM>, the opening area <NUM> of the first cover <NUM> is provided by the first beam 52b and the second beam 52c, and the cushion member <NUM> is bonded to the first cover while lying along the first beam 52b and the second beam 52c. This can provide the specific configuration to dispose the cushion member <NUM> in such a manner as to lie along the non-opening portion of the opening portion <NUM>.

With the speaker apparatus <NUM>, the cushion member <NUM> has the bent beam-shaped portion 80a which is provided to lie along the non-opening portion at the sound radiation center C of the speaker <NUM>. As a result, since the bent beam-shaped portion 80a functions as a beam on the cushion member <NUM>, the in-plane strength of the cushion member <NUM> in the plan view can be increased, and further, the working efficiency in affixing the cushion member <NUM> to the first cover <NUM> can also be improved.

In addition, with the speaker apparatus <NUM>, the cushion member <NUM> and the saran net <NUM> are disposed close to each other. As a result, in the case that the saran net <NUM> vibrates, the saran net <NUM> comes to interfere with the cushion member <NUM>, whereby the vibration of the saran net <NUM> is absorbed by the cushion member <NUM>, thereby making it possible to prevent or suppress the occurrence of resonance in the saran net <NUM> more effectively.

Further, the electronic keyboard instrument <NUM> which constitutes an electronic musical instrument having the speaker apparatus <NUM> can prevent or suppress the occurrence of resonance effectively at the time of sound radiation, thereby making it possible to make sound radiation of good quality.

The fabrication method of the speaker apparatus <NUM> includes the first disposition step of disposing the first cover <NUM> having the opening areas <NUM> each made up of the multiple opening portions in such a manner that the opening areas <NUM> are superposed above the corresponding sound radiation ports 10a of the speakers <NUM>, the second disposition step of disposing the second cover <NUM> to be superposed on the side of the first cover <NUM> which is opposite to the side thereof which faces the speakers <NUM> in such a manner as to surround the opening areas <NUM> of the first cover <NUM>, and the bonding step of bonding the saran net <NUM> to the second cover <NUM> in such a manner as to cover the first cover <NUM> and the side of the second cover <NUM> which is opposite to the side thereof which faces the speakers <NUM>. In the bonding step, the second cover <NUM> and the saran net <NUM> are bonded together at the area A1 with the first adhesive B1 and at the areas A2 which surround the opening areas <NUM> of the first cover <NUM> with the second adhesive B2 having the higher bonding strength than that of the first adhesive B1.

With the fabrication method described above, by executing the first disposition step and the second disposition step, the first cover <NUM>, the second cover <NUM>, and the saran net <NUM> can be assembled together with the sufficient gap secured between the sound radiation ports 10a of the speakers <NUM> and the opening areas <NUM> of the first cover <NUM>, and the saran net <NUM> in the position where the saran net <NUM> is superposed above the sound radiation ports 10a of the speakers <NUM>. Further, by executing the bonding step, the saran net <NUM> can be bonded to the second cover <NUM> with the large tension exerted on the areas A3 which are surrounded by the portions bonded with the second adhesive B2, compared with the area A1 bonded with the first adhesive B1. As a result, the large tension is exerted on the saran net <NUM> while securing the gap between the sound radiation ports 10a of the speakers <NUM> and the saran net <NUM>, whereby the speaker apparatus <NUM> can be fabricated which can prevent or suppress the occurrence of resonance therein.

With the fabrication method of the speaker apparatus <NUM>, in the bonding step, the saran net <NUM> is bonded to the second cover <NUM> with the tension exerted on at least the areas A3 of the saran net <NUM> which are surrounded by the portions bonded with the second adhesive B2. As a result, in the bonding step, the larger tension can be exerted on the saran net <NUM> at the areas A3, thereby making it possible to fabricate the speaker apparatus <NUM> which can prevent or suppress the occurrence of resonance therein more effectively.

Next, referring to <FIG>, a speaker apparatus (sound radiation apparatus)<NUM> according to a modified example of the present disclosure will be described. The modified example of the present disclosure differs in that a cushion member <NUM> has a different shape from that of the cushion member <NUM> according to the application example of the present disclosure. The other configurations of the modified example are similar to those of the application example of the present disclosure, and hence, the description thereof will be omitted here. As shown in <FIG>, in the cushion member <NUM> according to the modified example of the present disclosure, a portion of the opening area <NUM> which surrounds the opening portion 53a provided in the position which is superposed above the sound radiation center C of the speaker <NUM> does not have the shape that follows the second beam 52c but is formed into a straight beam-shaped portion (a beam-shaped portion) 180a having a straight-line shape extending in a left-right direction. Although given the straight-line shape, the cushion member <NUM> according to the modified example of the present disclosure can provide the same advantageous effect as that of the cushion member <NUM> according to the application example of the present disclosure. Further, the cushion member <NUM> of the modified example of the present disclosure incorporates the straight beam-shaped portion 180a described above, thereby making it possible not only to increase the in-plane strength in the plan view but also to improve the working efficiency in affixing the cushion member <NUM> to the first cover <NUM>.

The application example and the modified example which have been described heretofore are presented as the examples, and hence, there is no intention to limit the scope of the present invention by the examples. The novel application example or modified example can be carried out in other various forms, and various omissions, replacements and modifications can be made thereto without departing from the scope of the present invention as claimed.

Claim 1:
A sound radiation apparatus, comprising:
a sound radiation unit (<NUM>);
a first member (<NUM>) having an opening area (<NUM>) which is provided in such a manner as to be superposed above at least a sound radiation port (10a) of the sound radiation unit (<NUM>) and which is made up of multiple opening portions at a location which is superposed above the sound radiation port (10a);
a second member (<NUM>) provided to be superposed on a side of the first member (<NUM>) which is opposite to a side thereof which faces the sound radiation unit in such a manner as to surround the opening area (<NUM>) of the first member (<NUM>); and
a covering member (<NUM>) configured to cover the first member (<NUM>) and a side of the second member (<NUM>) which is opposite to a side thereof which faces the sound radiation unit and bonded to the second member (<NUM>), characterised in that
the second member (<NUM>) and the covering member (<NUM>) are bonded together at an area (A1) on the second member (<NUM>) which excludes a portion surrounding a circumference of the opening area (<NUM>) of the first member (<NUM>) with a first adhesive (B1) and at an area (A2) on the second member (<NUM>) which surrounds the circumference of the opening area (<NUM>) of the first member (<NUM>) with a second adhesive (B2) having a higher bonding strength than a bonding strength of the first adhesive (B1) .