Speaker grill assembly and portable wireless communication apparatus

Abstract

To provide a technique that achieves both function, as a sound passage, of a dustproof sheet provided on a speaker grill and drainage property of the speaker grill.SOLUTION: A speaker grill assembly includes a front panel having a speaker grill with a plurality of slits extending parallel to one another formed, and a dustproof sheet that is on the inner surface side of the front panel and covers a predetermined area including at least the plurality of slits. The front panel has a drainage groove that is formed on the inner surface of the front panel and extends to intersect with the plurality of slits.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a speaker grill assembly and a portable wireless communication device. [Background technology]

[0002] Patent Document 1 discloses a technology that uses a beep sound to expel water that has entered a speaker grill. It shows. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6040561 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it will not function as a sound conductor until it outputs a beep and drains the water that has entered the inside. remains impaired. The object of the present invention is to provide a dustproof sheet for a speaker grill that functions as a sound passage and a speaker grill that functions as a sound passage. - To provide a technology that achieves both good drainage of the grill. [Means for solving the problem]

[0005] According to the present invention, a speaker grill having a plurality of slits extending parallel to each other is provided. a front panel having at least the plurality of slits on an inner surface side of the front panel; and a dustproof sheet covering a predetermined area including the front panel. A drain groove is formed on the inner surface of the panel so as to extend so as to intersect with the plurality of slits. R , Speech A car grill assembly is provided. Effect of the Invention

[0006] According to the present invention, the function of the dustproof sheet provided on the speaker grill as a sound passage and the function of the speaker grill as a sound passage are -It is possible to achieve both the drainage properties of the grill and the above. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a perspective view of a handheld transceiver. [Diagram 2] FIG. 2 is an exploded perspective view of the handheld transceiver. [Diagram 3] FIG. 2 is an exploded perspective view of the handheld transceiver as viewed from another angle. [Figure 4] FIG. 2 is an exploded perspective view of the speaker grill assembly. [Diagram 5] FIG. 2 is a rear view of the speaker grill. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 5. [Figure 8] FIG. 4 is a rear view of the speaker grill with the grill-side double-sided tape superimposed on the speaker grill. [Figure 9] FIG. 4 is a rear view of the speaker grill with a low water-repellent sheet superimposed on the speaker grill. [Figure 10] FIG. 2 is a rear view of the speaker grill assembly. [Figure 11] 11 is a cross-sectional view taken along line IX-IX in FIG. [Figure 12] FIG. 12 is an enlarged view of part A in FIG. [Figure 13] FIG. 13 corresponds to FIG. 12 and shows a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. 2 and 3 are exploded perspective views of the handheld transceiver 1. The handheld transceiver 1 is a specific example of a wireless communication device capable of two-way communication. be. As shown in FIG. 1 to FIG. 3, the handheld transceiver 1 includes a front panel 2 and a dustproof shield. The keyboard 3, the speaker 4, the control board 5, the rear panel 6, and the battery cover 7 are The front panel 2 and the rear panel 6 constitute the housing 8 of the handheld transceiver 1. is. The front panel 2 is typically made of resin and is disposed so as to face the speaker 4. The speaker grill 9 is shown by a two-dot chain line in FIG. The speaker grill 9 is a part of the front panel 2 and is made up of multiple parallel speakers. The speaker grill 9 is a plate having four slits 10. As shown in FIG. 1 to FIG. 3, the speaker grill 9 is 4 and the grill inner surface 9a facing the inner surface of the front panel 2, and the grill inner surface 9a and the opposite side and a grill outer surface 9b on the exterior side of the front panel 2. Hereinafter, the direction in which the multiple slits 10 extend as shown in FIG. The direction in which the slits 10 are arranged in a row is referred to as the "upper-lower direction." The plate thickness direction, which is perpendicular to both the width direction and the up-down direction, is referred to as the "front-back direction." The grill outer surface 9b of the speaker grill 9 shown in FIG. The grill inner surface 9a of the speaker grill 9 shown in FIG. It corresponds to a surface. The front panel 2 has an upper surface 2a and a lower surface 2b. It is formed near the upper surface 2a of the panel 2. Hereinafter, the direction of looking at the upper surface 2a from the lower surface 2b will be referred to as " The opposite is called "upper" and the opposite is called "lower." The handheld transceiver 1 typically has It is used with the upper surface 2a facing up. As shown in FIG. 2 and FIG. 3, the handheld transceiver 1 includes a front panel 2, a dustproof shield, 3, speaker 4, control board 5, rear panel 6, and battery cover 7 in the order listed. It is constructed by stacking it backwards. The front panel 2 and the rear panel 6 are connected to each other, so that the dustproof sheet 3 and the speaker The car 4 houses a control board 5. The speaker 4 is supported by the control board 5. The front panel 2 and the rear panel 6 are sandwiched between them in the front-to-rear direction. Supported by Panel 6. As shown in FIG. 3, the dustproof sheet 3 is attached to the inner surface 9a of the grill so as to cover the multiple slits 10. As shown in FIG. 2 and FIG. 3, the dustproof sheet 3 is attached to the grill side double-sided tape 11 and It includes a low water-repellent sheet 12, a double-sided tape for lamination 13, and a highly water-repellent sheet 14. Grill side The double-sided tape 11, the low water-repellent sheet 12, the double-sided tape for lamination 13, and the highly water-repellent sheet 14 are The sheets are stacked in the order shown, starting from the front panel 2 to the speaker 4. The dustproof sheet 3 is Functionally, it has a two-layer structure consisting of a low water-repellent sheet 12 and a highly water-repellent sheet 14 . The low water repellent sheet 12 is a sheet having low water repellency, and is typically made of polyethylene terephthalate. The contact angle between the low water repellent sheet 12 and water is typically less than 90 degrees. The low water-repellent sheet 12 typically has a thickness of 0.2 mm to 1.0 mm. The highly water-repellent sheet 14 is a sheet having high water repellency, and is typically made of polyethylene or polypropylene. The highly water-repellent sheet 14 is a sheet made of propylene. The contact angle between the highly water-repellent sheet 14 and water is typically 90 degrees or more. The thickness of the highly water-repellent sheet 14 is typically 0.2 mm to 1.0 mm. The highly water-repellent sheet 14 is configured in a mesh shape. The diaphragm of the speaker 4 is contaminated by small foreign objects that pass through the multiple slits 10. The mesh structure of the speaker 4 provides a dust-proof function to prevent dust from entering the speaker. It also functions as a sound passage. Furthermore, the highly water-repellent sheet 14 has high water repellency. A water film is unlikely to form on the surface of the highly water-repellent sheet 14, and the function of the highly water-repellent sheet 14 as a sound passage is not impaired. It will never be damaged. The grill-side double-sided tape 11 is used to attach the low water-repellent sheet 12 to the grill inner surface 9a of the speaker grill 9. The double-sided tape 13 for lamination is used to bond the highly water-repellent sheet 14 to the low water-repellent sheet The double-sided tape 11 for the grill and the double-sided tape 13 for lamination are used for bonding the grill. Alternatively, an adhesive may be used. In this embodiment, the speaker grill 9 and the dustproof sheet 3 of the front panel 2 are This constitutes a car grill assembly 100. Next, the structure of the speaker grill 9 will be described in detail with reference to Figures 4 to 7. 5 is an exploded perspective view of the speaker grill assembly 100. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5; Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 5; It is. As shown in FIGS. 6 and 7, the plurality of slits 10 are arranged in the thickness direction of the speaker grill 9, i.e. That is, the speaker casing 1 is formed so as to penetrate the speaker grill 9 in the front-rear direction. As shown in FIGS. 5 and 6, a drain groove 15 is formed on the inner surface of the front panel 2. In detail, the grill inner surface 9a of the speaker grill 9 has a plurality of slits 10 intersecting each other. As shown in FIG. 1, the drain groove 15 is formed to extend in the vertical direction. Specifically, the drain groove 15 is formed of a plurality of The inner space of each slit 10 is formed by the inner circumferential wall of the slit 10. The inner space of the drain groove 15 is connected to the inner space of the drain groove 15. The inner bottom surface of the drain groove 15 is provided with a plurality of slits. 10. Therefore, as shown in FIG. 6, the drain groove 15 is divided into a plurality of slips. The inner bottom surface 15a is divided by the grooves 10. , a plane perpendicular to the front-to-rear direction. As shown in Figures 5 and 6, the speaker grill 9 includes a plurality of thin-walled portions 16. The fleshy portion 16 is a portion that is located alternately with the plurality of slits 10 in the vertical direction. As shown in the figure, the thin-walled portions 16 are adjacent to the drain grooves 15 in the front-rear direction. The thin-walled portions 16 are portions that are thinned due to the presence of the drain grooves 15. The thickness of the portion 16 is greater than the thickness of the portion of the speaker grill 9 where the drain groove 15 is not formed. For the sake of convenience, the thin-walled portions 16 will be referred to as thin-walled portions 16a in the upward direction. , thin-walled portion 16b, thin-walled portion 16c, thin-walled portion 16d, and thin-walled portion 16e. As shown in FIG. The thin wall portions 16a, 16b, 16c, and 16d are all oriented upward. Specifically, the thin-walled portion 16a and the thin-walled portion 16 b, the thin-walled portion 16c, and the thin-walled portion 16d each have a V-shaped portion 17 that is convex upward. That is, the inner wall surface of the slit 10 is inclined upward from the surface located on the lower side of the front panel. With the above-mentioned configuration, the thin-walled portion 16a and the thin-walled portion 16b are formed in a V-shape. If a water film is formed in the slit 10, the thin wall portion 16a and the thin wall portion 16b may be formed. Even if a water film is formed in the slit 10, the film is easily broken. slit 10 between thin-walled portion 16c and thin-walled portion 16d; slit 10 between thin-walled portion 16d and thin-walled portion 16c; The same applies to the slits 10 between the fleshy parts 16e. The function of the thin wall portion 16a, the thin wall portion 16b, and the thin wall portion 16c are not impaired. 6c and the thin-walled portion 16d may be formed so as to become thinner toward the bottom. good. Next, the dustproof sheet 3 will be described in detail with reference to FIG. 4 and FIG. 8 to FIG. As shown in FIG. 4, the dustproof sheet 3 is typically made of a grill-side double-sided tape 11 and a low water-repellent sheet. The laminate 12, the double-sided tape for lamination 13, and the highly water-repellent sheet 14 are stacked in the order shown and integrated. In this state, the speaker grill 9 is attached to the inner grill surface 9a of the front panel 2. . However, for the sake of convenience, in FIG. 8, only the grill-side double-sided tape 11 is shown as being connected to the speaker grill 9. By overlapping the two, the shape of the grille side double-sided tape 11 is explained. By showing only the water-repellent sheet 12 overlapping the speaker grill 9, the shape of the low water-repellent sheet 12 can be seen. explain. FIG. 8 shows the state in which grill-side double-sided tape 11 is placed on speaker grill 9. As shown in FIG. 8, the grill-side double-sided tape 11 surrounds the plurality of slits 10 and is In other words, the grill-side double-sided tape 11 is formed in a U-shape that opens toward the drainage side. A first tape portion 11a extending in the vertical direction and located on one side of the groove 15 in the width direction; and a drainage groove. A second tape portion 11b is located on the other side of the first tape portion 15 in the width direction and extends in the vertical direction. and a third tape portion 11c connecting the upper end of the second tape portion 11b and the upper end of the third tape portion 11a. In short, the grill side double-sided tape 11 has a plurality of slits 10 and drainage grooves 15 and a front and rear The shape is formed in an area excluding the multiple slits 10 and the drain groove 15 so that they do not face each other as much as possible in the direction. It has been made. FIG. 9 shows a state in which a low water repellent sheet 12 is placed on the speaker grill 9. As shown in FIG. 1, the low water repellent sheet 12 is formed so as not to impede the function of the slits 10 as sound passages. The low water repellent sheet 1 has a plurality of openings 18 corresponding to the plurality of slits 10. 2 includes a plurality of opposing portions 19 that face a plurality of inner bottom surfaces 15a of the drain groove 15 in the front-rear direction. The openings 18 and the opposing portions 19 are arranged alternately in the vertical direction. 9 is a thin wall portion 16a and a facing portion 19a facing the thin wall portion 16b, a thin wall portion 19b facing the thin wall portion 16b, and a thin wall portion 19c facing the thin wall portion 16c. The laminated laminate includes a facing portion 19c facing the thick portion 16c and a facing portion 19d facing the thin portion 16d. The shape of the double-sided tape 13 is the same as that of the low water-repellent sheet 12, so a description thereof will be omitted. FIG. 10 shows a rear view of the speaker grill assembly 100. Thus, the highly water-repellent sheet 14 is disposed so as to cover the multiple slits 10. The drain groove 15 extends from the inside to the outside of the outer periphery 3a of the dustproof sheet 3. The drain groove 15 has an exposed portion 15 b that is not covered by the dustproof sheet 3 . FIG. 11 is a cross-sectional view taken along the line IX-IX in FIG. 10. In FIG. 11, all components of the dustproof sheet 3 are The thickness of each component is emphasized. As shown in FIG. 11, the dustproof sheet 3 is arranged to face a plurality of slits 10 in the front-rear direction. A plurality of slit opposing portions 20 and a plurality of inner bottom surfaces 15a of the drain grooves 15 are arranged in the front-rear direction. The drainage groove facing portions 21 are made up of a plurality of thin-walled portions. 16 in the front-rear direction. The sections 21 are alternately positioned in the up-down direction. Each slit facing portion 20 has a single-layer structure consisting of only the highly water-repellent sheet 14. The slit grill facing surface 20a of the slit facing portion 20 on the speaker grill 9 side is made of highly water-repellent The slits 20 are arranged on the speaker grill 9 side of the panel 14. The contact angle between the slit grille facing surface 20a and water is equal to the contact angle between the highly water-repellent sheet 14 and water. stomach. Each drainage groove facing portion 21 is made of a highly water-repellent sheet 14, a double-sided tape for lamination 13, and a low water-repellent sheet 12. Therefore, the drain grooves on the speaker grill 9 side of each drain groove facing portion 21 are The grill-facing surface 21a corresponds to the surface of the low water-repellent sheet 12 facing the speaker grill 9. Therefore, the contact angle between the drain grill facing surface 21a of each drain facing portion 21 and water is 12 is equal to the contact angle with water. As a result, as shown in FIG. 12, the drain groove grill facing surface 21a of each drain groove facing portion 21 and the water The contact angle θ1 between the slit grille facing surface 20a of each slit facing portion 20 and water is Therefore, the function of the dustproof sheet 3 provided on the speaker grill 9 as a sound passage is This allows both the function and the drainage of the speaker grill 9 to be achieved. This technical effect will be explained in detail with reference to the following. As shown in FIG. 12, water entering the speaker grill 9 from the outside through each slit 10 When the adhesive is attached to the slit grill facing surface 20a of each slit facing portion 20, the slit grill Due to the water repellency of the opposing surface 20a, the water droplets W become nearly spherical. The slit grill facing surface 20a is unlikely to be covered with a water film. The function of the facing portion 20 as a sound passage is not impaired. On the other hand, water that has entered the speaker grill 9 from the outside through each slit 10 is discharged through each drain groove. When the dust adheres to the drain groove grill facing surface 21a of the facing portion 21, the dust adheres to the drain groove grill facing surface 20a of the facing portion 21. The water droplets W spread in a gentle hill-like shape due to the water content. Water droplets W adhering to the grill-facing surface 21a simultaneously come into contact with the corresponding inner bottom surface 15a of the drain groove 15. This is because the thickness Wd of the water drop W in the front-back direction is suppressed. Please refer to FIG. 13. FIG. 13 shows a comparative example of this embodiment. As shown in FIG. 1, in the comparative example, the highly water-repellent sheet 14 and the multiple inner bottom surfaces 15a of the drainage grooves 15 are That is, the highly water-repellent sheet 14 and the thin-walled portions 16 face each other in the front-rear direction. Therefore, the water repellency of the highly water repellent sheet 14 causes the balls to adhere to the highly water repellent sheet 14. Since the water droplet W having a similar shape is thick in the front-rear direction, it contacts both the thin wall portions 16 at the same time. When the water droplets W come into contact with the highly water-repellent sheet 14 and any of the thin portions 16 at the same time, Even if W is subjected to vertical vibration, it will not be drained along the drain 15 and will tend to remain in place. become. In contrast, referring back to FIG. 12, in this embodiment, the drain groove grill facing surface of each drain groove facing portion 21 Since the water droplets W adhering to the drain groove 15 are unlikely to contact the inner surface of the drain groove 15 at the same time, the water droplets W This promotes drainage through the speaker grille 5. The water droplet W that has moved downward via the drain groove 15 shown in FIG. The water moves from the exposed portion 15b of the water heater 15 into the housing 8 of the handheld transceiver 1, and is then discharged to a drainage tank (not shown). The electric current is discharged to the outside of the handheld transceiver 1 via a path. As shown in FIG. 12, the dust particles adhering to the drain grill facing surface 21a of each drain facing portion 21 were Since the thickness Wd of the water droplet W in the front-rear direction is suppressed, the water droplet W is easily discharged from each drain groove opposing portion 21. The water channel grill facing surface 21a and the inner bottom surface 15a of the drainage channel 15 should not be in contact with each other at the same time. It is no longer necessary to form the drain groove 15 deep, and the entire handheld transceiver 1 This contributes to compactness in the front-to-rear direction. The preferred embodiments of the present disclosure have been described above, and have the following features. The speaker grill assembly 100 has a plurality of slits 10 extending parallel to each other. A front panel 2 having a speaker grill 9 formed thereon, and a and a dustproof sheet 3 that covers a predetermined area including at least the plurality of slits 10. The front panel 2 extends so as to intersect with a plurality of slits 10 on the inner surface of the front panel 2. The bottom surface of the drainage groove 15 is divided by a plurality of slits 10. The inner surface of the front panel 2 of the dustproof sheet 3 is divided into a plurality of inner bottom surfaces 15a. The surface facing the slits 10 has a plurality of slit facing portions at positions facing the slits 10, respectively. 20 and a plurality of drain groove facing portions 21 at positions facing the plurality of inner bottom surfaces 15a, respectively. The contact angle θ1 between each drain groove facing portion 21 and water is According to the above-mentioned configuration, each slit facing portion 20 is covered with water in a film-like manner. Since the sound passages of the plurality of slit opposing portions 20 are not easily broken, the function of the plurality of slit opposing portions 20 as sound passages is not impaired. In addition, the water droplets W adhering to the opposing portions 21 of the drain grooves are simultaneously dropped onto the corresponding inner bottom surfaces 15a of the drain grooves 15. Since the water droplets W adhering to the drain groove opposing portions 21 are less likely to come into contact with the drain groove opposing portions 21, the water droplets W are more likely to be discharged. The function of the dustproof sheet 3 provided on the speaker grill 9 as a sound passage and the function of the speaker grill It is possible to achieve both drainage performance of 9. As shown in FIGS. 1 to 4, the speaker grill assembly 100 includes a speaker grill. The speaker grill 9 is disposed opposite the speaker 4. The speaker grill 9 has a plurality of slits 10 extending parallel to each other. The speaker grill 9 has a grill inner surface 9a facing the speaker 4 and a grill inner surface 9b facing the speaker 4. The dustproof sheet 3 covers the multiple slits 10. As shown in Figs. 5 to 7, the grill inner surface 9a is bonded to the grill inner surface 9a. A drain groove 15 is formed so as to extend so as to intersect with the plurality of slits 10. The drain groove 15 is 11, the inner bottom surface 15a is divided by a plurality of slits 10. As shown in FIG. 1, the dustproof sheet 3 has a plurality of slit facing portions 2 that face the plurality of slits 10. 0, a plurality of drainage groove opposing portions 21 respectively opposing the plurality of inner bottom surfaces 15a of the drainage grooves 15, The plurality of slit opposing portions 20 and the plurality of drainage groove opposing portions 21 are arranged in the longitudinal direction of the drainage groove 15. As shown in FIG. 12, the speaker grooves of each drain groove facing portion 21 are arranged alternately along the The contact angle θ1 between the drainage groove grill facing surface 21a on the slit 9 side and water is This is smaller than the contact angle θ2 between the surface 20a of the slit grille facing the speaker grille 9 and water. According to the above-mentioned configuration, the slit grille facing surface 20a of each slit facing portion 20 is not easily damaged by water. Since it is difficult to cover the slits in a film-like manner, the function of the slit opposing portions 20 as sound paths is impaired. Furthermore, water droplets W adhering to the drain groove grill facing surface 21a of each drain groove facing portion 21 are not discharged. Since it is difficult for the water groove 15 to simultaneously come into contact with the corresponding inner bottom surface 15a of the water groove 15, the drain groove grill opposing surface 21 Therefore, the dustproof sheet provided on the speaker grill 9 is easily discharged. This makes it possible to achieve both the function of the sound passage of the speaker 3 and the drainage property of the speaker grill 9. As shown in FIG. 11, the dustproof sheet 3 is made of a mesh-shaped highly water-repellent sheet 14 (first sheet). The water-repellent sheet 14 is laminated on the low water-repellent sheet 12 (second sheet). The dust sheet 3 is arranged such that the low water-repellent sheet 12 is positioned between the high water-repellent sheet 14 and the speaker grill 9. The grille inner surface 9a is bonded to the grille inner surface 9a so that the grille inner surface 9a is adhered .... The holes 14 are not covered by the low water repellent sheet 12 and are exposed to the speaker grill 9 side. In the drain groove facing portion 21, the highly water-repellent sheet 14 is covered with the low water-repellent sheet 12. According to this configuration, the dust-proof sheet 3 can be provided with partially different contact angles at low cost. In addition, instead of forming the dustproof sheet 3 in a multi-layer structure as in the above embodiment, the dustproof sheet 3 In this case, the contact angle between the dust-proof sheet 3 and water may be different at each portion. In addition, different portions of the dustproof sheet 3 may be subjected to different surface treatments. As shown in FIG. 6, the speaker grill 9 has a thickness The slits 10 and the drainage groove 15 are arranged alternately in the longitudinal direction of the drainage groove 15. The drain groove 15 has a plurality of thin-walled portions 16 arranged in the longitudinal direction thereof. The thin portion 16c (first thin portion) and the thin portion 16d (second thin portion) are adjacent to each other. The portion 16c is formed so as to become thinner as it approaches the thin-walled portion 16d. According to this configuration, a water film is unlikely to be formed 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 sound of the multiple slits 10 Its function as a road will not be compromised. As shown in FIG. 10, the drain groove 15 is formed from the inside to the outside of the outer periphery 3a of the dustproof sheet 3. According to the above-mentioned configuration, the dustproof sheet 3 does not hinder the drainage from the drain groove 15. stomach. The handheld transceiver 1 (portable wireless communication device) is It is equipped with 100 speakers and 4 speakers. [Explanation of symbols]

[0009] 1 Handheld transceiver 2 Front Panel 2a Top side 2b Bottom side 3 Dustproof sheet 3a Outer rim 4 speakers 5 Control Board 6 Rear Panel 7 Battery cover 8. Cabinet 9 Speaker Grill 9a Grill inner surface 9b Grill exterior 10 Slit 11 Grill side double-sided tape 11a 1st Tape Section 11b 2nd Tape Section 11c 3rd Tape Section 12 Low water repellent sheet 13 Double-sided tape for lamination 14 Highly water-repellent sheet 15. Drain 15a Inner bottom surface 15b Exposed part 16 Thin section 16a Thin section 16b Thin wall part 16c Thin section 16d Thin section 16e Thin section 17 V-shaped part 18 Aperture 19 Opposing part 19a Opposite part 19b Opposite part 19c Opposite part 19d Opposite section 20 Slit facing part 20a Slit grill facing surface 21 Drain facing part 21a Drain grill facing surface 100 Speaker Grill Assembly θ1 Contact angle θ2 Contact angle W water drop Wd Thickness

Claims

1. A front panel having a speaker grill with multiple slits extending parallel to each other Ru and A predetermined area including at least the plurality of slits is covered on the inner surface of the front panel. and a dustproof sheet, The front panel has an inner surface on which a plurality of slits are intersected. A drainage groove is formed extending to Speaker grill assembly.

2. The dustproof sheet is a mesh-like two-layer structure consisting of a highly water-repellent first sheet and a less water-repellent second sheet. and The dustproof sheet is arranged in such a manner that, from the inner surface of the front panel, the second sheet, then the first sheet, They are located in the order of 2. The speaker grill assembly of claim 1.

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