Speaker grille assembly and portable wireless communication device

Abstract

The present invention relates to a speaker grille assembly and a portable wireless communication device. A speaker grille assembly comprises: a front panel having a speaker grille; and a dustproof sheet on the inner surface side of the front panel. The front panel has a drainage groove formed on the inner surface of the front panel, which crosses and extends with a plurality of slits, and the bottom surface of the formed drainage groove is divided by the plurality of slits to form a plurality of inner bottom surfaces. On the surface of the dustproof sheet opposite to the inner surface of the front panel, there are a plurality of slit opposing portions at positions respectively opposite to the plurality of slits, and a plurality of drainage groove opposing portions at positions respectively opposite to the plurality of inner bottom surfaces. The contact angle of each drainage groove opposing portion with water is smaller than the contact angle of each slit opposing portion with water.

Description

Technical Field

[0001] The invention relates to a speaker grille assembly and a portable wireless communication device. Background Art

[0002] Patent Document 1 discloses a technique for discharging water that has intruded into a speaker grille using a beep sound.

[0003] Patent document 1: Japanese Patent No. 6040561. Summary of the invention

[0004] Problems to be solved by the invention

[0005] However, until the BEEP sound is output to discharge the water that has intruded into the interior, the function of the sound channel remains impaired.

[0006] Means used to solve problems

[0007] According to the present embodiment, a speaker grille assembly is provided, comprising: a front panel having a speaker grille, wherein a plurality of slits extending parallel to each other are formed on the speaker grille; and a dustproof sheet covering at least a specified range including the plurality of slits on the inner surface side of the front panel, wherein the front panel has drainage grooves formed on the inner surface of the front panel and extending crosswise with the plurality of slits, wherein the bottom surfaces of the drainage grooves are divided by the plurality of slits to form a plurality of inner bottom surfaces, and the surface of the dustproof sheet opposite to the inner surface of the front panel has a plurality of slit opposing portions at positions respectively opposite to the plurality of slits, and has a plurality of drainage groove opposing portions at positions respectively opposite to the plurality of inner bottom surfaces, wherein a contact angle of each drainage groove opposing portion with water is smaller than a contact angle of each slit opposing portion with water.

[0008] According to the present embodiment, a portable wireless communication device is provided, comprising a speaker grille assembly and a speaker, wherein the speaker grille assembly comprises: a front panel having a speaker grille, on which a plurality of slits extending parallel to each other are formed; and a dustproof sheet covering at least a specified range including the plurality of slits on the inner surface side of the front panel, wherein the front panel is formed with drainage grooves extending crosswise with the plurality of slits on the inner surface of the front panel, wherein the bottom surface of the drainage grooves is divided by the plurality of slits to form a plurality of inner bottom surfaces, and on the surface of the dustproof sheet opposite to the inner surface of the front panel, a plurality of slit opposing portions are provided at positions respectively opposite to the plurality of slits, and a plurality of drainage groove opposing portions are provided at positions respectively opposite to the plurality of inner bottom surfaces, wherein a contact angle of each drainage groove opposing portion with water is smaller than a contact angle of each slit opposing portion with water. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, advantages and features will become more apparent from the following description of certain embodiments in conjunction with the accompanying drawings, in which:

[0010] Figure 1 It is a stereogram of a handheld walkie-talkie.

[0011] Figure 2 It is an exploded perspective view of a handheld walkie-talkie.

[0012] Figure 3 It is an exploded perspective view of the handheld walkie-talkie viewed from other angles.

[0013] Figure 4 is an exploded perspective view of the speaker grille assembly.

[0014] Figure 5 is a rear view of the speaker grille.

[0015] Figure 6 yes Figure 5 A cross-sectional view taken along line VI-VI.

[0016] Figure 7 yes Figure 5 A cross-sectional view taken along line VII-VII.

[0017] Figure 8 1 is a rear view of the speaker grille, and is a diagram showing a state where the grille-side double-sided tape is overlapped on the speaker grille.

[0018] Fig. 9 It is a rear view of the speaker grille and is a diagram showing a state where the low waterproof sheet is overlapped on the speaker grille.

[0019] Fig.10 is a rear view of the speaker grille assembly.

[0020] Fig.11 yes Fig.10 A cross-sectional view taken along line IX-IX.

[0021] Fig.12 yes Fig.11 Magnified view of part A in FIG.

[0022] Fig.13 is with Fig.12 The corresponding figures are figures showing comparative examples. DETAILED DESCRIPTION

[0023] Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. Figure 1 A perspective view of a handheld intercom 1 is shown. Figure 2 and Figure 3The figure shows an exploded perspective view of a handheld intercom 1. The handheld intercom 1 is a specific example of a wireless communication device capable of two-way communication.

[0024] like Figures 1 to 3 As shown, the handheld intercom 1 includes: a front panel 2, a dustproof sheet 3, a speaker 4, a control substrate 5, a rear panel 6 and a battery cover 7. The front panel 2 and the rear panel 6 constitute a housing 8 of the handheld intercom 1.

[0025] The front panel 2 is generally made of resin and includes a speaker grill 9 disposed to face the speaker 4. Figure 1 The speaker grille 9 is indicated by a double-dotted line. The speaker grille 9 is a part of the front panel 2 and is a plate body having a plurality of slits 10 parallel to each other. In this embodiment, the speaker grille 9 has four slits 10. Figures 1 to 3 As shown, the speaker grille 9 has: a grille inner surface 9a, which is opposite to the speaker 4 on the inner surface side of the front panel 2; and a grille outer surface 9b, which is located on the side opposite to the grille inner surface 9a, that is, the appearance side of the front panel 2.

[0026] The following, such as Figure 1 As shown, the direction in which the plurality of slits 10 extend is referred to as the "width direction". The direction in which the plurality of slits 10 are arranged in a row is referred to as the "up-down direction". Furthermore, the plate thickness direction of the speaker grille 9, i.e., the direction orthogonal to either the width direction or the up-down direction, is referred to as the "front-back direction". Figure 1 The grille outer surface 9b of the speaker grille 9 shown corresponds to the front surface of the speaker grille 9. Figure 3 The grille inner surface 9 a of the illustrated speaker grille 9 corresponds to the back surface of the speaker grille 9 .

[0027] The front panel 2 has an upper surface 2a and a lower surface 2b. The speaker grille 9 is formed close to the upper surface 2a of the front panel 2. Hereinafter, the direction from the lower surface 2b to the upper surface 2a is referred to as "upward", and the opposite direction is referred to as "downward". The handheld intercom 1 is usually used with the upper surface 2a facing upward.

[0028] like Figure 2 and Figure 3 As shown, the handy intercom 1 is constructed by stacking a front panel 2, a dustproof sheet 3, a speaker 4, a control board 5, a rear panel 6, and a battery cover 7 in the order described in the front-rear direction.

[0029] The front panel 2 and the rear panel 6 are connected to each other to accommodate the dustproof sheet 3, the speaker 4 and the control board 5. The speaker 4 is supported by the control board 5. The control board 5 is supported by the front panel 2 and the rear panel 6 by being sandwiched between the front panel 2 and the rear panel 6 in the front-back direction.

[0030] like Figure 3 As shown, the dustproof sheet 3 is bonded to the inner surface 9a of the grille to cover the plurality of slits 10. Figure 2 and Figure 3 As shown, the dustproof sheet 3 includes a grille side double-sided tape 11, a low waterproof sheet 12, a laminating double-sided tape 13, and a high waterproof sheet 14. The grille side double-sided tape 11, the low waterproof sheet 12, the laminating double-sided tape 13, and the high waterproof sheet 14 are overlapped in this order from the front panel 2 toward the speaker 4. The dustproof sheet 3 is functionally a double-layer structure having the low waterproof sheet 12 and the high waterproof sheet 14.

[0031] The low waterproof sheet 12 is a sheet with low waterproofness, and is usually a sheet made of polyethylene terephthalate. The contact angle between the low waterproof sheet 12 and water is usually less than 90 degrees. The thickness of the low waterproof sheet 12 is usually 0.2 mm to 1.0 mm.

[0032] The highly waterproof sheet 14 is a sheet with high waterproof properties, and is usually a sheet made of polyethylene or polypropylene. The contact angle between the highly waterproof sheet 14 and water is usually above 90 degrees. The thickness of the highly waterproof sheet 14 is usually 0.2 mm to 1.0 mm. Moreover, the highly waterproof sheet 14 is configured in a mesh shape. Thus, the highly waterproof sheet 14 performs a dustproof function, preventing small foreign objects that can pass through the plurality of slits 10 from contaminating the vibration plate of the speaker 4, and at the same time, the speaker 4 functions as a sound channel through the mesh structure. In addition, since the highly waterproof sheet 14 has high waterproof properties, it is difficult to form a water film on the surface of the highly waterproof sheet 14, and the function of the highly waterproof sheet 14 as a sound channel will not be damaged.

[0033] The grille-side double-sided tape 11 is used to adhere the low waterproof sheet 12 to the grille inner surface 9a of the speaker grille 9. The laminating double-sided tape 13 is used to adhere the high waterproof sheet 14 to the low waterproof sheet 12. Instead of the grille-side double-sided tape 11 and the laminating double-sided tape 13, an adhesive may be used.

[0034] In the present embodiment, the speaker grill 9 of the front panel 2 and the dustproof sheet 3 constitute a speaker grill assembly 100 .

[0035] Next, refer to Figures 4 to 7 The structure of speaker grill 9 will be described in detail. Figure 4 is an exploded perspective view of the speaker grill assembly 100 . Figure 5 is a rear view of the speaker grille 9. Figure 6 yes Figure 5 A cross-sectional view taken along line VI-VI. Figure 7 yes Figure 5 A cross-sectional view taken along line VII-VII.

[0036] like Figure 6 and Figure 7As shown, a plurality of slits 10 are formed to penetrate the speaker grill 9 in the plate thickness direction of the speaker grill 9, that is, in the front-rear direction.

[0037] like Figure 5 and Figure 6 As shown, a drainage groove 15 is formed on the inner surface of the front panel 2. Specifically, a drainage groove 15 extending in the vertical direction is formed on the grille inner surface 9a of the speaker grille 9 so as to intersect with the plurality of slits 10. Specifically, the drainage groove 15 extends in a manner of penetrating the inner peripheral wall of the plurality of slits 10. Therefore, the internal space of each slit 10 is connected to the internal space of the drainage groove 15. The inner bottom surface of the drainage groove 15 is divided by the plurality of slits 10. Therefore, as shown in FIG. Figure 6 As shown, the drain groove 15 has a plurality of inner bottom surfaces 15a divided by a plurality of slits 10. The plurality of inner bottom surfaces 15a are all surfaces perpendicular to the front-rear direction.

[0038] like Figure 5 and Figure 6 As shown in FIG. 1 , the speaker grill 9 includes a plurality of thin-walled portions 16. The plurality of thin-walled portions 16 are portions that are alternately arranged with the plurality of slits 10 in the vertical direction. Figure 6 As shown, the plurality of thin-walled portions 16 are portions adjacent to the drainage groove 15 in the front-to-back direction. That is, the plurality of thin-walled portions 16 are portions that are thinned due to the presence of the drainage groove 15. Therefore, the plate thickness of each thin-walled portion 16 is smaller than the plate thickness of the portion of the speaker grille 9 where the drainage groove 15 is not formed. In the following, for the sake of convenience, the plurality of thin-walled portions 16 are referred to as thin-walled portion 16a, thin-walled portion 16b, thin-walled portion 16c, thin-walled portion 16d, and thin-walled portion 16e in order from top to bottom. Figure 6 As shown, the thin-walled portion 16a, the thin-walled portion 16b, the thin-walled portion 16c, and the thin-walled portion 16d are all formed to become thinner as they move upward. Specifically, the thin-walled portion 16a, the thin-walled portion 16b, the thin-walled portion 16c, and the thin-walled portion 16d all have a V-shaped portion 17 that protrudes upward. That is, the inner wall surface of the slit 10 is formed in a V-shape that protrudes upward from the surface located on the lower side of the front panel. Through the above structure, it is difficult to form a water film in the slit 10 between the thin-walled portion 16a and the thin-walled portion 16b, and even if a water film is formed in the slit 10 between the thin-walled portion 16a and the thin-walled portion 16b, the water film is easily broken. The slit 10 between the thin-walled portion 16b and the thin-walled portion 16c, the slit 10 between the thin-walled portion 16c and the thin-walled portion 16d, and the slit 10 between the thin-walled portion 16d and the thin-walled portion 16e are also the same. Therefore, the function of the multiple slits 10 as sound channels will not be damaged. In addition, the thin-walled portion 16 a , the thin-walled portion 16 b , the thin-walled portion 16 c , and the thin-walled portion 16 d may all be formed so as to become thinner as they go downward.

[0039] Next, refer to Figure 4 , Figures 8 to 13The dustproof sheet 3 will be described in detail.

[0040] like Figure 4 As shown, the dustproof sheet 3 is usually pasted on the grille inner surface 9a of the speaker grille 9 of the front panel 2 in a state where the grille side double-sided tape 11, the low waterproof sheet 12, the stacking double-sided tape 13, and the high waterproof sheet 14 are overlapped and integrated in the recorded order.

[0041] However, for the sake of illustration, Figure 8 In FIG. 1 , only the grille-side double-sided tape 11 is overlapped with the speaker grille 9 to illustrate the shape of the grille-side double-sided tape 11. Fig. 9 In FIG. 1 , only the low waterproof sheet 12 and the speaker grill 9 are shown overlapped, thereby explaining the shape of the low waterproof sheet 12.

[0042] Figure 8 FIG. 1 shows a state where the grille-side double-sided tape 11 is overlapped on the speaker grille 9. Figure 8 As shown, the grille-side double-sided tape 11 surrounds the plurality of slits 10 and is formed into a U-shape that opens downward. That is, the grille-side double-sided tape 11 includes: a first tape portion 11a, which is located closer to one side in the width direction than the drainage groove 15 and extends in the up-down direction; a second tape portion 11b, which is located closer to the other side in the width direction than the drainage groove 15 and extends in the up-down direction; and a third tape portion 11c, which connects the upper end of the first tape portion 11a and the upper end of the second tape portion 11b. In short, the grille-side double-sided tape 11 is formed in a range other than the plurality of slits 10 and the drainage groove 15 so as not to be opposed to the plurality of slits 10 and the drainage groove 15 as much as possible in the front-rear direction.

[0043] Fig. 9 FIG. 1 shows a state where a low waterproof sheet 12 is overlapped on the speaker grille 9. Fig. 9 As shown, the low waterproof sheet 12 has a plurality of openings 18 corresponding to the plurality of slits 10, respectively, so that the function of the plurality of slits 10 as sound channels is not impaired. The low waterproof sheet 12 includes a plurality of opposing portions 19 that are opposed to the plurality of inner bottom surfaces 15a of the drain groove 15 in the front-back direction. The plurality of openings 18 and the plurality of opposing portions 19 are alternately arranged in the up-down direction. The plurality of opposing portions 19 include an opposing portion 19a opposed to the thin-walled portion 16a, an opposing portion 19b opposed to the thin-walled portion 16b, an opposing portion 19c opposed to the thin-walled portion 16c, and an opposing portion 19d opposed to the thin-walled portion 16d. The shape of the double-sided tape 13 for lamination is the same as that of the low waterproof sheet 12, so the description thereof is omitted.

[0044] Fig.10 1 shows a rear view of the speaker grill assembly 100. Fig.10As shown, the highly waterproof sheet 14 is arranged to cover the plurality of slits 10. In addition, the drainage groove 15 extends from the inner side to the outer side of the outer peripheral edge 3a of the dustproof sheet 3. Therefore, the drainage groove 15 has an exposed portion 15b not covered by the dustproof sheet 3.

[0045] Fig.11 yes Fig.10 A cross-sectional view of the IX-IX line. Fig.11 In FIG. 1 , the thicknesses of all the components constituting the dustproof sheet 3 are emphasized and depicted.

[0046] like Fig.11 As shown, the dustproof sheet 3 includes: a plurality of slit opposing portions 20 respectively opposing the plurality of slits 10 in the front-to-back direction, and a plurality of drain groove opposing portions 21 respectively opposing the plurality of inner bottom surfaces 15a of the drain groove 15 in the front-to-back direction. The plurality of drain groove opposing portions 21 are respectively opposed to the plurality of thin-walled portions 16 in the front-to-back direction. The plurality of slit opposing portions 20 and the plurality of drain groove opposing portions 21 are alternately arranged in the up-down direction.

[0047] Each slit facing portion 20 is a single-layer structure composed only of the high waterproof sheet 14. Therefore, the slit grill facing surface 20a of each slit facing portion 20 located on the speaker grill 9 side is equivalent to the surface of the high waterproof sheet 14 located on the speaker grill 9 side. Therefore, the contact angle between the slit grill facing surface 20a of each slit facing portion 20 and water is equal to the contact angle between the high waterproof sheet 14 and water.

[0048] Each drain groove facing portion 21 has a three-layer structure consisting of a high waterproof sheet 14, a double-sided tape for lamination 13, and a low waterproof sheet 12. Therefore, a drain groove grille facing surface 21a of each drain groove facing portion 21 located on the speaker grille 9 side is equivalent to a surface of the low waterproof sheet 12 located on the speaker grille 9 side. Therefore, the contact angle between the drain groove grille facing surface 21a of each drain groove facing portion 21 and water is equal to the contact angle between the low waterproof sheet 12 and water.

[0049] As mentioned above, Fig.12 As shown in FIG. 1 , the contact angle θ1 between the drain groove grille facing surface 21a of each drain groove facing portion 21 and water is smaller than the contact angle θ2 between the slit grille facing surface 20a of each slit facing portion 20 and water. Therefore, the function of the dustproof sheet 3 provided on the speaker grille 9 as a sound channel and the drainage performance of the speaker grille 9 can be taken into consideration. Fig.12 as well as Fig.13 , the technical effect is described in detail.

[0050] like Fig.12As shown in FIG. 1 , when water that has penetrated from the outside of the speaker grille 9 through each slit 10 adheres to the slit grille facing surface 20a of each slit facing portion 20, the slit grille facing surface 20a becomes a nearly spherical water droplet W due to the waterproofness of the slit grille facing surface 20a. That is, the slit grille facing surface 20a of each slit facing portion 20 is unlikely to be covered with water in a film-like state. Therefore, the functions of the plurality of slit facing portions 20 as sound channels are not impaired.

[0051] On the other hand, when water that has penetrated from the outside of the speaker grille 9 through the slits 10 adheres to the drain groove grille facing surface 21a of each drain groove facing portion 21, it becomes a water droplet W that spreads out in a gentle hill shape due to the hydrophilicity of the drain groove grille facing surface 21a. That is, it is difficult for the water droplet W that has adhered to the drain groove grille facing surface 21a of each drain groove facing portion 21 to simultaneously contact the corresponding inner bottom surface 15a of the drain groove 15. This is because the thickness Wd of the water droplet W in the front-rear direction can be suppressed.

[0052] Here, please refer to Fig.13 . Fig.13 A comparative example of this embodiment is shown. Fig.13 As shown, in the comparative example, the high waterproof sheet 14 and the plurality of inner bottom surfaces 15a of the drainage groove 15 are opposite in the front-to-back direction. That is, the high waterproof sheet 14 and the plurality of thin-walled portions 16 are opposite in the front-to-back direction. Therefore, due to the waterproof property of the high waterproof sheet 14, the nearly spherical water droplet W attached to the high waterproof sheet 14 has a large thickness in the front-to-back direction, and is therefore likely to contact any of the thin-walled portions 16 at the same time. When the water droplet W contacts the high waterproof sheet 14 and any of the thin-walled portions 16 at the same time, even if the water droplet W is subjected to vertical vibration, it will not be drained along the drainage groove 15 and is likely to stay there.

[0053] In contrast, return Fig.12 In this embodiment, it is difficult for water droplets W attached to the drainage groove grille facing surface 21a of each drainage groove facing portion 21 to contact the inner surface of the drainage groove 15 at the same time, so it is possible to promote the drainage of water droplets W through the drainage groove 15. That is, it is possible to achieve high drainage performance of the speaker grille 9. Then, after Fig.11 The water droplets W moving downward in the drainage groove 15 shown in the figure move from the exposed portion 15b of the drainage groove 15 into the housing 8 of the portable intercom 1, and are discharged to the outside of the portable intercom 1 through a drainage passage not shown in the figure.

[0054] In addition, if Fig.12As shown, since the thickness Wd of the water droplets W attached to the drain groove grille opposing surface 21a of each drain groove opposing portion 21 in the front-to-back direction is suppressed, there is no need to form the drain groove 15 deeper in order to prevent the water droplets W from contacting the drain groove grille opposing surface 21a of each drain groove opposing portion 21 and any inner bottom surface 15a of the drain groove 15 at the same time. Accordingly, it helps to make the handheld intercom 1 as a whole compact in the front-to-back direction.

[0055] As mentioned above, although the preferred embodiment of the present invention has been described, the above-mentioned embodiment has the following characteristics.

[0056] The speaker grille assembly 100 comprises: a front panel 2 having a speaker grille 9, and a plurality of slits 10 extending parallel to each other are formed in the speaker grille 9; and a dustproof sheet 3 covering at least a predetermined range including the plurality of slits 10 on the inner surface side of the front panel 2. On the front panel 2, a drainage groove 15 extending and crossing the plurality of slits 10 is formed on the inner surface of the front panel 2, and the bottom surface of the formed drainage groove 15 is divided by the plurality of slits 10 to form a plurality of inner bottom surfaces 15a. On the surface of the dustproof sheet 3 facing the inner surface of the front panel 2, a plurality of slit facing portions 20 are provided at positions facing the plurality of slits 10, respectively, and a plurality of drainage groove facing portions 21 are provided at positions facing the plurality of inner bottom surfaces 15a, respectively. The contact angle θ1 of each drainage groove facing portion 21 with water is smaller than the contact angle θ2 of each slit facing portion 20 with water. According to the above structure, since each slit opposing portion 20 is difficult to be covered with water in a film shape, the function of the plurality of slit opposing portions 20 as a sound channel is not impaired, and the water droplets W attached to each drainage groove opposing portion 21 are difficult to contact the corresponding inner bottom surface 15a of the drainage groove 15 at the same time, so it is possible to promote the discharge of the water droplets W attached to each drainage groove opposing portion 21. Therefore, it is possible to take into account both the function of the dustproof sheet 3 provided on the speaker grille 9 as a sound channel and the drainage property of the speaker grille 9.

[0057] like Figures 1 to 4 As shown, the speaker grille assembly 100 includes a speaker grille 9 and a dustproof sheet 3. The speaker grille 9 is arranged to face the speaker 4. A plurality of slits 10 extending parallel to each other are formed on the speaker grille 9. The speaker grille 9 has a grille inner surface 9a facing the speaker 4 and a grille outer surface 9b located on the side opposite to the grille inner surface 9a. The dustproof sheet 3 is bonded to the grille inner surface 9a to cover the plurality of slits 10. Figures 5 to 7 As shown in FIG. 1 , a drainage groove 15 is formed on the inner surface 9a of the grille, and extends across the plurality of slits 10. The drainage groove 15 has a plurality of inner bottom surfaces 15a divided by the plurality of slits 10. Fig.11As shown, the dustproof sheet 3 includes a plurality of slit-opposing portions 20 respectively opposed to the plurality of slits 10 and a plurality of drain groove-opposing portions 21 respectively opposed to the plurality of inner bottom surfaces 15a of the drain groove 15. The plurality of slit-opposing portions 20 and the plurality of drain groove-opposing portions 21 are alternately arranged along the length direction of the drain groove 15. Fig.12 As shown, the contact angle θ1 between the drain groove grill facing surface 21a of each drain groove facing portion 21 located on the speaker grill 9 side and water is smaller than the contact angle θ2 between the slit grill facing surface 20a of each slit facing portion 20 located on the speaker grill 9 side and water.

[0058] According to the above structure, since the slit grille facing surface 20a of each slit facing portion 20 is difficult to be covered with water in a film shape, the function of the plurality of slit facing portions 20 as a sound channel is not impaired, and the water droplets W attached to the drain groove grille facing surface 21a of each drain groove facing portion 21 are difficult to contact the corresponding inner bottom surface 15a of the drain groove 15 at the same time, so the discharge of the water droplets W attached to the drain groove grille facing surface 21a can be promoted. Therefore, the function of the dustproof sheet 3 provided on the speaker grille 9 as a sound channel and the drainage property of the speaker grille 9 can be taken into consideration.

[0059] In addition, if Fig.11 As shown, the dustproof sheet 3 includes a mesh-shaped high waterproof sheet 14 (first sheet) and a low waterproof sheet 12 (second sheet) overlapping the high waterproof sheet 14. The dustproof sheet 3 is bonded to the grille inner surface 9a so that the low waterproof sheet 12 is located between the high waterproof sheet 14 and the speaker grille 9. In each slit-opposing portion 20, the high waterproof sheet 14 is not covered by the low waterproof sheet 12 and is exposed to the speaker grille 9 side. In each drain groove-opposing portion 21, the high waterproof sheet 14 is covered by the low waterproof sheet 12. According to the above structure, it is possible to realize locally different contact angles of the dustproof sheet 3 at a low cost.

[0060] It should be noted that the dustproof sheet 3 may also be a single-layer structure, instead of the multi-layer structure of the dustproof sheet 3 in the above embodiment. In this case, in order to make the contact angle between the dustproof sheet 3 and water different in each part, the dustproof sheet 3 may also be subjected to different surface treatments according to each part.

[0061] In addition, if Figure 6As shown, the speaker grille 9 has a plurality of thin-walled portions 16 adjacent to the drain groove 15 in the plate thickness direction of the speaker grille 9 and alternately arranged in the length direction of the plurality of slits 10 and the drain groove 15. The plurality of thin-walled portions 16 include a thin-walled portion 16c (first thin-walled portion) and a thin-walled portion 16d (second thin-walled portion) adjacent to the drain groove 15 in the length direction. The thin-walled portion 16c is formed to become thinner as it approaches the thin-walled portion 16d. According to the above structure, it is difficult to form a water film in the slit 10 between the thin-walled portion 16c and the thin-walled portion 16d. The same applies to the other slits 10. Therefore, the function of the plurality of slits 10 as sound channels is not impaired.

[0062] In addition, if Fig.10 As shown, the drainage groove 15 extends from the inner side to the outer side of the outer peripheral edge 3a of the dustproof sheet 3. According to the above structure, the dustproof sheet 3 does not hinder the drainage from the drainage groove 15.

[0063] The handy intercom 1 (portable wireless communication device) has the above-mentioned speaker grill assembly 100 and the speaker 4.

[0064] While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention can be practiced with various modifications within the spirit and scope of the appended claims and the invention is not limited to the examples described above.

[0065] Furthermore, the scope of the claims is not limited by the above-described embodiments.

[0066] Furthermore, it is noted that Applicant's intent is to encompass equivalents of all claim elements, even if amended later during prosecution.

Claims

1. A speaker grille assembly, comprising: a front panel having a speaker grille on which a plurality of slits extending parallel to each other are formed; as well as The dustproof sheet covers at least a predetermined range including the plurality of slits on the inner surface side of the front panel. The front panel has a drainage groove formed on the inner surface of the front panel, the drainage groove extending and crossing the plurality of slits, and the bottom surface of the drainage groove is divided by the plurality of slits to form a plurality of inner bottom surfaces. The dustproof sheet has a surface facing the inner surface of the front panel, and has a plurality of slit facing portions at positions facing the plurality of slits, and a plurality of drainage groove facing portions at positions facing the plurality of inner bottom surfaces. The dustproof sheet is in a mesh shape and has a double-layer structure of a highly waterproof first sheet and a low waterproof second sheet. The dustproof sheets are arranged in the order of the second sheet and then the first sheet from the inner surface of the front panel, The second sheet material is opened at each slit-opposing portion, The contact angle between each drain groove facing portion and water is smaller than the contact angle between each slit facing portion and water.

2. The speaker grill assembly of claim 1, wherein: The inner wall surface of the slit is formed in a V-shape that protrudes upward from a surface located on the lower side of the front panel.

3. The speaker grill assembly of claim 2, wherein: The drainage groove extends from the dustproof sheet to the outside.

4. A portable wireless communication device, comprising a speaker grille assembly and a speaker, wherein the speaker grille assembly comprises: The front panel has a speaker grille, and a plurality of slits extending parallel to each other are formed on the speaker grille; as well as A dustproof sheet covers at least a predetermined range including the plurality of slits on the inner surface side of the front panel, The front panel has a drainage groove formed on the inner surface of the front panel, the drainage groove extending and crossing the plurality of slits, and the bottom surface of the drainage groove is divided by the plurality of slits to form a plurality of inner bottom surfaces. The dustproof sheet has a surface facing the inner surface of the front panel, and has a plurality of slit facing portions at positions facing the plurality of slits, and a plurality of drainage groove facing portions at positions facing the plurality of inner bottom surfaces. The dustproof sheet is in a mesh shape and has a double-layer structure of a highly waterproof first sheet and a low waterproof second sheet. The dustproof sheets are arranged in the order of the second sheet and then the first sheet from the inner surface of the front panel, The second sheet material is opened at each slit-opposing portion, The contact angle between each drain groove facing portion and water is smaller than the contact angle between each slit facing portion and water.

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