JP2008199225A - Electronic apparatus and mounting structure of microphone in same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a dust-proof property, a water-proof property, the reduction of wind noise, enhancement of wind pressure resistance, prevention of sticking with sharp-edged things, and improvement of tone quality at a low cost. <P>SOLUTION: A microphone 25 mounted on a circuit board is joined to an inside surface of a front case 9 in a close contact state through a frame-like double-sided adhesive sheet stuck to a peripheral edge of a ceiling face so that a microphone sound hole 25a is kept a prescribed distance apart from a case sound hole 9a for transmission, and a dust-proof mesh sheet subjected to water-repellent treatment is stuck to an inside edge part of the case sound hole 9a for transmission through a frame-like double-sided adhesive sheet, and a stratified space constituting a sound path is formed by the double-sided adhesive sheets. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a microphone mounting structure and an electronic device in an electronic device, and more particularly, to a microphone mounting structure and an electronic device that constitute a transmitter in an electronic device having a telephone call function such as a mobile phone.

  2. Description of the Related Art Conventionally, for example, in a foldable mobile phone, a receiving unit having a speaker that outputs a received voice is provided at the upper end of the front side of the upper case (the inner side when folded). A speech transmission unit having a microphone for inputting a transmission voice is provided at the lower end, and an operator (speaker) uses the reception unit and the transmission unit in close proximity to the ear and the mouth, respectively. , Is configured to allow calls.

  The microphone of the transmitter is composed of, for example, a condenser microphone, is attached to the circuit board and stored in the lower housing, and is arranged so that the microphone sound hole overlaps the case sound hole formed in the lower housing. Then, the transmitted voice is inputted from the case sound hole, and the sound wave propagates to the microphone sound hole communicating with the case sound hole. This sound wave further reaches the diaphragm, and a voltage corresponding to the sound pressure is generated.

However, when dust or moisture enters the lower housing from the case sound hole, it easily reaches the microphone sound hole and enters the microphone body, causing deterioration in sound quality, failure, and the like.
Further, for example, when wind or airflow is blown from the case sound hole, it has been input to the microphone as wind noise. In addition, for example, when a folding cellular phone is suddenly closed, the diaphragm may be damaged by excessive wind pressure.
In addition, when a long and narrow sharp object such as a wire enters from the case sound hole, the microphone sound hole may be reached as it is and the microphone may be damaged.

In order to reduce wind noise, the microphone is wrapped with a rubber vibration-proof material, and a recess is formed in the vibration-proof material to form a sound path (see, for example, Patent Document 1). Further, a case sound hole and a microphone are provided. Techniques have been proposed in which the sound holes are arranged so as not to overlap with each other (see, for example, Patent Document 1 and Patent Document 2).
In addition, a technique has been proposed in which a part of the sound path is formed as a curved path to prevent an elongated sharp object such as a wire from entering the microphone (for example, see Patent Document 3).
Japanese Utility Model Publication No. 5-20491 Japanese Utility Model Publication No. 60-32887 JP 2004-328756 A

The first problem to be solved is that the above-described conventional technology is difficult to reduce the cost and to reduce the thickness and size of the device while maintaining dust resistance and waterproofing. .
That is, in order to sufficiently cope with dustproofing and waterproofing, material costs required for components such as a microphone are increased, and a complicated structure is adopted, resulting in increased manufacturing costs. Furthermore, even if costs are imposed on component parts and mounting structures, it has become difficult to meet the demand for thinner and smaller devices.

Further, the second problem is that it is difficult to reduce the thickness and size of the device while reducing the wind noise and providing the wind pressure resistance.
In addition, the third problem is that it is difficult to reduce the thickness and size of the device with the above-described conventional technology while preventing the piercing by the sharp object.

In addition, the fourth problem is that the above-described prior art increases the cost in order to improve the sound quality by reducing howling and noise.
In other words, in order to improve sound quality by reducing howling and noise, it is not possible to achieve with a simple configuration, adopting a complicated structure, adjusting acoustic resistance, reducing howling, and electrically frequency characteristics Therefore, it is necessary to improve the sound quality, and the cost is increased.

The present invention has been made in view of the above-described circumstances, and can implement a microphone mounting structure and an electronic device in an electronic device that can perform dustproofing and waterproofing at low cost, and can contribute to thinning and downsizing of the device. The first object is to provide equipment.
A second object of the present invention is to provide a microphone mounting structure and an electronic device in an electronic device that can reduce wind noise, improve wind pressure resistance, and contribute to thinning and downsizing of the device. It is said.

It is a third object of the present invention to provide a microphone mounting structure and an electronic device in an electronic device that can prevent piercing by a sharp object and contribute to thinning and miniaturization of the device.
Another object of the present invention is to provide a microphone mounting structure and an electronic device in an electronic device that can improve sound quality at low cost.

  In order to solve the above problem, the invention according to claim 1 relates to a microphone mounting structure in which a microphone is mounted in a casing of an electronic device, and the casing is provided with a first sound collection hole. The microphone has a second sound collection hole, and the second sound collection hole faces the inner surface of the housing where the first sound collection hole is provided, and the microphone has the second sound collection hole. The sound input from the first sound collection hole is placed between the inner surface of the housing and the microphone so as not to overlap the first sound collection hole. It is characterized by the formation of a layered space that constitutes the leading sound path.

  According to a second aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to the first aspect, wherein the microphone is adhered to the inner surface of the casing by a frame-like double-sided adhesive sheet, and the layered space is The side is formed by being surrounded by the inner surface of the double-sided pressure-sensitive adhesive sheet.

  According to a third aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to the first or second aspect, wherein a dustproof sheet-like member is disposed on the sound path.

  According to a fourth aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to the first, second, or third aspect, the distance between the first sound collecting hole and the second sound collecting hole, and the above The volume or cross-sectional area of the layered space is characterized by being set to a predetermined value.

  According to a fifth aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to the third or fourth aspect, wherein the dustproof sheet-like member is a mesh-like member made of a woven fabric.

  According to a sixth aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to the fifth aspect, wherein the dustproof sheet-like member is a mesh-like member having a predetermined roughness. It is said.

  A seventh aspect of the invention relates to a microphone mounting structure in the electronic device according to the sixth aspect, wherein the distance between the first sound collecting hole and the second sound collecting hole, the volume of the layered space, or The cross-sectional area and the mesh roughness of the mesh member are set to predetermined values or types in accordance with the frequency characteristics of the transmission level of the microphone.

  According to an eighth aspect of the present invention, there is provided a microphone mounting structure in the electronic device according to any one of the fourth to seventh aspects, wherein a distance between the first sound collecting hole and the second sound collecting hole is provided. Is characterized by being set to approximately 1 mm or more and approximately 3 mm or less.

  The invention according to claim 9 relates to a microphone mounting structure in the electronic device according to any one of claims 3 to 8, wherein the dustproof sheet-like member is subjected to a water repellent process. It is a feature.

  A tenth aspect of the present invention relates to a microphone mounting structure in the electronic device according to any one of the third to ninth aspects, wherein the dustproof sheet-like member is formed of a frame-like double-sided pressure-sensitive adhesive sheet. It is characterized by being adhered to the inner surface of the body.

  According to an eleventh aspect of the present invention, an electronic apparatus includes the microphone mounting structure of the electronic apparatus according to any one of the first to tenth aspects.

According to the configuration of the present invention, the microphone is disposed such that the second sound collection hole does not overlap the first sound collection hole of the housing, and the sound path is provided between the inner surface of the housing and the microphone. Since the layered space that constitutes is formed, dustproofing and waterproofing can be performed at low cost, and the device can be reduced in thickness and size.
The second sound collection hole is disposed so as not to overlap the first sound collection hole of the housing, and a layered space constituting the sound path is formed between the inner surface of the housing and the microphone. Therefore, wind noise can be reduced, wind pressure resistance can be improved, and the device can be reduced in thickness and size.

The second sound collection hole is disposed so as not to overlap the first sound collection hole of the housing, and a layered space constituting the sound path is formed between the inner surface of the housing and the microphone. Therefore, it is possible to prevent piercing by a sharp object and to contribute to thinning and downsizing of the device.
The second sound collection hole is disposed so as not to overlap the first sound collection hole of the housing, and a layered space constituting the sound path is formed between the inner surface of the housing and the microphone. Therefore, the sound quality can be improved at a low cost.

It is arranged so as not to overlap the first sound collection hole of the housing, and a layered space that forms the sound path is formed between the inner surface of the housing and the microphone, so that it is dust-proof and waterproof at low cost. In addition, the first purpose of contributing to thinning and downsizing of the device was realized.
In addition, it is arranged so as not to overlap the first sound collection hole of the housing, and a layered space that forms the sound path is formed between the inner surface of the housing and the microphone, thereby reducing wind noise. As a result, the second object of improving the wind pressure resistance and contributing to the thinning and miniaturization of the device has been realized.

In addition, a layered space constituting a sound path is formed between the inner surface of the housing and the microphone so as not to overlap the first sound collection hole of the housing, so that a piercing by a sharp object is formed. In addition to preventing this, the third object of contributing to thinning and miniaturization of the device has been realized.
In addition, it is arranged so as not to overlap the first sound collection hole of the housing, and a layered space forming the sound path is formed between the inner surface of the housing and the microphone, so that sound quality can be reduced at a low cost. The 4th objective of improving was realized.

FIG. 1 is a front view of an open state showing a configuration of a foldable mobile phone according to a first embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the mobile phone, and FIG. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 5 is an enlarged view showing the portion B in FIG. 6 is an enlarged view showing a portion C of FIG. 4, and FIGS. 7 and 8 are explanatory views for explaining the configuration of the microphone mounting structure of the mobile phone, which is disassembled into each component. FIG. 9 and FIG. 10 are diagrams for explaining the function of the microphone mounting structure, and show the relationship between the frequency of the transmitted voice and the sound pressure level of the transmitted voice. FIG. 11 is an explanatory diagram for explaining the function of the microphone mounting structure.
As shown in FIG. 1, the cellular phone 1 of this example includes a foldable casing 2, and an upper unit 3 and a lower unit 4 are coupled to each other by a hinge portion 5 so as to be foldable. Configured.

The upper housing 6 (lower housing 7) constituting the housing 2 is made of a synthetic resin molded product such as ABS resin, for example, and as shown in FIG. 1, each of the front cases 8 (9) constituting the inner surface side. And the rear case 11 (12) constituting the outer surface side, and the assembled front case 8 (9) and rear case 11 (12) are fitted by ribs, or a female screw, a male screw or the like. Various components are housed inside or assembled by fastening with a fixing tool.
As shown in FIG. 1, a reception case sound hole 8 a is formed in the upper part of the front case 8, and a transmission case sound hole 9 a is formed in the lower part of the front case 9.

  As shown in FIGS. 1 and 2, the mobile phone 1 includes a control unit 14 that controls each component of the mobile phone body, and a storage unit that stores processing programs executed by the control unit 14, various data, and the like. 15, an antenna 16 that transmits and receives radio waves, a wireless communication unit 17 that is used to perform a call and data communication in accordance with a predetermined protocol, a receiver unit 18 that has, for example, a speaker that outputs a received voice, and a transmitted voice. A transmitter 19 having a microphone 25 for input, a voice output unit 21 for outputting a ring tone when receiving an incoming call, and a liquid crystal display device disposed on the inner side (inner side) when folded, for example, a function setting screen And a display unit 22 for displaying a standby screen and the like, and an operation unit 23 including a number of various operation keys for inputting numbers and characters.

In the transmitter section 19, the microphone 25 has a microphone case sound hole 9 a so that the microphone sound hole 25 a keeps a predetermined distance d from the case case sound hole 9 a formed in the lower part of the front case 9. It is arranged on the inner surface (back surface) side of the nearby front case 9.
That is, in the microphone mounting structure 26 of this example, as shown in FIGS. 3 to 8, the microphone 25 mounted on the circuit board 27 so that the microphone sound hole 25a faces the front case 9 side is provided on the ceiling surface 25b. The microphone sound hole 25a is maintained at a predetermined distance d from the transmission case sound hole 9a (in an offset state) via the frame-shaped double-sided adhesive sheet 28 attached to the periphery. A dust-proof mesh sheet 29 that is bonded to the inner surface (back surface) in a close contact state, and has a water-repellent finish on the ceiling surface 9p of the recess 9b for storage formed at the inner surface side edge of the transmission case sound hole 9a. Are laminated via a frame-shaped double-sided pressure-sensitive adhesive sheet 31, and the double-sided pressure-sensitive adhesive sheet 28 forms a layered sky that forms a sound path from the transmission case sound hole 9a to the microphone sound hole 25a. 32 is formed is schematically configured.

  A transmission case sound hole 9a is formed at the lower portion of the front case 9, and a storage recess 9b for storing the dustproof mesh sheet 29 is formed at the inner side edge of the transmission case sound hole 9a. ing. The depth of the storage recess 9 b is substantially the same as the thickness of the dust-proof mesh sheet 29 and the double-sided pressure-sensitive adhesive sheet 31 overlapped.

The microphone 25 is composed of, for example, a condenser microphone, is mounted on the circuit board 27 and accommodated in the lower housing 7, and the microphone sound hole 25 a is inserted into the transmission case sound hole 9 a formed in the front case 9. Are arranged so that they do not overlap, the transmitted sound is input from the transmitting case sound hole 9a, and the sound wave propagates to the microphone sound hole 25a communicating with the transmitting case sound hole 9a. A voltage corresponding to the sound pressure is generated by reaching the diaphragm.
The dustproof mesh sheet 29 is made of, for example, a plain woven fabric using nylon fibers (polyamide fibers), is water-repellent, and has an eye roughness of 330 to 500 (in this example, 380).
Here, when the number is 500 or more, the transmission level is uniformly reduced over the entire frequency band. When the number is 330 or less, the transmission level is too coarse and the effect of offset does not appear.
The thickness of the dustproof mesh sheet 29 is at least about 0.1 mm or less.

Both the double-sided pressure-sensitive adhesive sheets 28 and 31 are formed in a frame shape (angular ring). The double-sided pressure-sensitive adhesive sheet 28 has a lower surface adhered to the peripheral edge of the ceiling surface 25b of the microphone 25, and an upper surface adhered to the rear surface 9q of the outer periphery of the storage recess 9b of the front case 9, and the dimensions (opening dimensions) within the frame are The size of the dustproof mesh sheet 29 is set larger.
The lower surface of the double-sided pressure-sensitive adhesive sheet 31 is adhered to the periphery of the upper surface of the dust-proof mesh sheet 29, and the upper surface is adhered to the periphery of the ceiling surface 9 p of the storage recess 9 b of the front case 9.

In this example, the separation (offset distance) d between the microphone sound hole 25a and the transmission case sound hole 9a, the cross-sectional area of the layered space 32, and the roughness (count) of the dustproof mesh sheet 29 are, for example, the microphone 25. Are set to predetermined values (types) in accordance with the frequency characteristics of the transmission level.
For example, the distance (offset distance) d between the microphone sound hole 25a and the transmission case sound hole 9a is approximately 2 mm. The vertical and horizontal dimensions of the layered space 32 are approximately 2 mm × 4 mm (the cross-sectional area is approximately 8 square mm). The height from the ceiling surface 25b of the microphone 25 to the back surface 9q of the front case 9 is approximately 0.1 mm, and the height from the ceiling surface 25b of the microphone 25 to the ceiling surface 9p of the storage recess 9b is 0. .2 mm to 0.25 mm. Further, the roughness of the mesh of the dustproof mesh sheet 29 is 330 to 500 (in this example, 380).

Here, the layered space 32 is set relatively wide so as to include the arrangement positions of the microphone sound hole 25a and the transmission case sound hole 9a in plan view, and to include the outer peripheral regions thereof.
In general, the greater the separation (offset distance) d, the lower the transmission sensitivity. However, particularly in a high frequency band, the acoustic resistance increases and the range of decrease increases (see FIG. 9).
Here, the distance (offset distance) d between the microphone sound hole 25a and the transmission case sound hole 9a, the cross-sectional area of the layered space 32, and the roughness of the mesh of the dust-proof mesh sheet 29 are defined as the frequency of the transmission level of the microphone 25. When appropriately set (selected) according to the characteristics, for example, as described above, when the layered space 32 is set to be relatively wide, a relatively high frequency is obtained without uniformly providing acoustic resistance over the entire frequency band. An acoustic resistance can be given only to the band (see FIG. 10).
As a result, the frequency characteristic is corrected, and the sound pressure level near the resonance frequency in a relatively high frequency band can be suppressed.
Note that. The frequency characteristics of the sound pressure level of the call voice can be adjusted by changing the roughness (count), material, etc. of the dustproof mesh sheet.

Next, functions of the cellular phone 1 of this example will be described with reference to FIGS. 9 to 11.
As shown in FIG. 11, the transmitted voice that has entered from the transmitting case sound hole 9a propagates along the propagation path K that passes through the dust-proof mesh sheet 29, passes through the layered space 32, and reaches the microphone sound hole 25a. To do. When the sound wave reaches the diaphragm of the microphone 25, a voltage corresponding to the sound pressure is generated.

  For example, when the layered space 32 is not expanded to the outer peripheral side of the transmission case sound hole 9a and the microphone sound hole 25a, as shown in FIG. 9, with respect to the transmission level curve L0 without offset, In the transmission level curves L1, L2, and L3 with an offset of 1 mm, an offset of 2 mm, and an offset of 3 mm, the transmission sensitivity decreases as the separation (offset distance) d increases, and the transmission level decreases in all frequency bands. In particular, the amount of decrease is large in a high frequency band.

  On the other hand, as in this example, the layered space 32 includes a microphone sound hole 25a and a transmission case sound hole 9a, and is set to be relatively wide so as to include an outer peripheral region thereof. When the mesh size of the mesh sheet 29 is appropriately selected, as shown in FIG. 10, the transmission level curve M1 having an offset of 2 mm is higher than the transmission level curve M0 having no offset. The transmission level is lowered only in the band.

  That is, particularly by appropriately setting the offset distance, the cross-sectional area of the layered space, and the roughness of the dust-proof mesh sheet according to the characteristics of the microphone 25, for example, the acoustic resistance is uniformly distributed over the entire frequency band. Without giving noise, the acoustic resistance is given only to a relatively high frequency band, the frequency characteristic is corrected, the sound pressure level near the resonance frequency of the relatively high frequency band is suppressed, and the sound quality of the call voice is surely improved. Can do.

  Further, when a foreign matter such as dust or moisture enters the lower case 7 from the transmission case sound hole 9a, first, the dustproof mesh sheet 29 prevents the entry into the back. Even if the microphone sound hole 25a is further penetrated, since the microphone sound hole 25a is disposed at a predetermined distance d from the transmission case sound hole 9a, the foreign matter reaches the microphone sound hole 25a. Is difficult.

  Further, when wind or air current is blown or excessive wind pressure is applied from the transmission case sound hole 9a, the sound passes through the dustproof mesh sheet 29 and is attenuated along the route to the microphone sound hole 25a. No wind or air current is blown directly into 25a, nor is excessive wind pressure applied.

  Further, when a long and narrow sharp object such as a wire is inserted from the transmission case sound hole 9a, first, it strikes against the dust-proof mesh sheet 29 and is prevented from entering the back. Even if the microphone sound hole 25a is further penetrated, since the microphone sound hole 25a is disposed at a predetermined distance d from the transmitting case sound hole 9a, the sharp object has its tip at the microphone sound hole. It is difficult to reach 25a.

Thus, according to the configuration of this example, the microphone 25 is disposed in the lower housing 7 so that the microphone sound hole 25a keeps the predetermined distance d from the transmission case sound hole 9a. Even if a foreign substance such as dust enters the lower housing 7 from the talk case sound hole 9a, it can be prevented from reaching the microphone sound hole 25a.
Further, since the dustproof mesh sheet 29 is pasted around the transmitting case sound hole 9a on the inner surface of the front case 9, it is possible to prevent entry of foreign matters such as dust while securing the sound path, Even if it enters, it can be reliably prevented from reaching the microphone sound hole 25a.

In addition, the microphone sound hole 25a is shifted so as not to overlap the transmission case sound hole 9a, and the dust-proof structure is realized at a low cost by a simple configuration in which the dust-proof mesh sheet 29 is provided. be able to.
Furthermore, since an extremely thin dust-proof mesh sheet 29 is employed and this dust-proof mesh sheet 29 is housed in the housing recess 9b formed around the transmission case sound hole 9a on the inner surface side of the front case 9, This can contribute to reduction in thickness and size.

Since the microphone 25 is disposed in the lower housing 7 so that the microphone sound hole 25a keeps a predetermined distance d from the transmission case sound hole 9a, moisture is transmitted from the transmission case sound hole 9a to the lower case. Even if it enters into the microphone 7, it can be prevented from reaching the microphone sound hole 25a.
Further, a dust-proof mesh sheet 29 having a water repellent finish is pasted around the transmitting case sound hole 9a on the inner surface of the front case 9, so that moisture can be prevented from entering while ensuring a sound path. Even if it has entered, it can be reliably prevented from reaching the microphone sound hole 25a.

In addition, such a waterproof structure can be realized at low cost, and it can contribute to thinning and downsizing of the device.
In this way, sound quality degradation, breakdowns, and the like can be prevented by reliably performing dustproofing and waterproofing.

Further, since the microphone 25 is disposed in the lower housing 7 so that the microphone sound hole 25a maintains a predetermined distance d from the transmission case sound hole 9a, the microphone sound hole 25a is directly connected to the microphone sound hole 25a. In addition, wind noise can be reduced and wind pressure resistance can be improved. In addition, since the dustproof mesh sheet 29 is inserted, for example, an excessive wind pressure can be reliably reduced.
In addition, the extremely thin dust-proof mesh sheet 29 is adopted, and the gap between the ceiling surface 25b of the microphone 25 constituting the sound path and the inner surface of the front case 9 is also set to be extremely narrow, so that the device is made thinner. Can contribute.

Further, since the microphone 25 is disposed in the lower housing 7 so that the microphone sound hole 25a keeps a predetermined distance d from the transmission case sound hole 9a, a long and narrow sharp object such as a wire is used for transmission. The case sound hole 9a can be pierced and prevented from entering through the microphone sound hole 25a. Moreover, the penetration of the sharp object into the lower housing can be reliably suppressed by inserting the dustproof mesh sheet 29.
In addition, the microphone sound hole 25a is arranged so as not to overlap with the transmitting case sound hole 9a, and only a very thin dust-proof mesh sheet 29 is provided to prevent the intrusion of sharp objects. Therefore, it can contribute to thickness reduction of an apparatus.

  Further, the transmission case sound hole 9a and the microphone sound hole 25a are separated from each other by a predetermined distance d, and the periphery of the ceiling surface 25b of the microphone 25 is connected to the back surface 9q of the front case 9 via the frame-shaped double-sided adhesive sheet 28. The layered space 32 having a relatively large predetermined volume (cross-sectional area) is formed by bonding in close contact, and the dustproof mesh sheet 29 having a predetermined roughness is connected to the ceiling surface 25b of the microphone 25 and the ceiling of the front case 9. Since it is inserted between the surface 9p, the frequency characteristics of the sound pressure level of the call voice can be improved, howling and noise can be reduced, and the sound quality of the call voice can be improved.

  In particular, by appropriately setting the offset distance d, the cross-sectional area of the layered space, and the coarseness of the dust-proof mesh sheet 29 according to the characteristics of the microphone 25, for example, uniform over the entire frequency band. Without applying acoustic resistance, the acoustic resistance is applied only to a relatively high frequency band, the frequency characteristics are corrected, the sound pressure level near the resonance frequency in the relatively high frequency band is suppressed, and the sound quality of the call voice is ensured. Can be improved.

In addition, the microphone sound hole 25a is shifted with respect to the transmission case sound hole 9a, the layered space 32 is formed using the double-sided adhesive sheet 29, and the low-cost component (component) is simply inserted. ), The sound quality can be easily improved at low cost.
Further, the frequency characteristics of the sound pressure level of the call voice can be easily adjusted by changing the roughness (count) of the dust-proof mesh sheet 29, the material, and the like.

Further, since the microphone 25 and the dust-proof mesh sheet 29 are adhered to the inner surface of the front case 9 using the double-sided adhesive sheets 28 and 31, a microphone mounting structure is formed. Therefore, the microphone mounting structure can be easily and quickly carried at low cost. The telephone 1 can be assembled and productivity can be improved.
In addition, a layered space with a very narrow gap is formed using the double-sided pressure-sensitive adhesive sheet 28, and a very thin dust-proof mesh sheet 29 is inserted, so that a microphone mounting structure can be formed in a narrow mounting space. This can contribute to the reduction in thickness.

FIG. 12 is a cross-sectional view showing the structure of the main part of a mobile phone according to the second embodiment of the present invention.
This example is greatly different from the first embodiment described above in that a lid member having an open central portion is inserted into the transmission case sound hole.
Since the other configuration is substantially the same as the configuration of the first embodiment described above, the same reference numerals as those used in FIG. 6 are used in FIG. 12 for the same components as those of the first embodiment. The explanation will be simplified.

In the microphone mounting structure of this example, as shown in FIG. 12, a transmission case sound hole 41a is formed in the lower part of the front case 41, and a dustproof portion is formed on the inner side edge of the transmission case sound hole 41a. A storage recess 41b for storing the mesh sheet 29 is formed, and a storage recess for storing a lid member 42 having an opening 42a at the center is formed on the outer side edge of the transmission case sound hole 41a. 41c is formed.
Here, the diameter of the inner case side (exit side) of the transmission case sound hole 41a is larger than the diameter of the transmission case sound hole 9a in the first embodiment, and on the outer side (inlet side), A lid member 42 is disposed in the housing recess 41c, and the opening 42a has substantially the same diameter as the transmitting case sound hole 9a.

According to the configuration of this example, substantially the same effect as that of the first embodiment described above can be obtained.
In addition, the diameter of the entrance of the transmission case sound hole is not changed, and foreign matter such as dust can be prevented from entering and the size of the transmission case sound hole constituting the sound path can be substantially enlarged. it can.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. Are also included in the present invention.
For example, in the above-described embodiments, the case where the present invention is applied to a mobile phone as an electronic device has been described. However, the present invention is not limited to a mobile phone, and for example, a portable information terminal having a transmission function even in a simple mobile phone (PHS) terminal. In general, the present invention can be applied to a portable electronic device in which a microphone is mounted, such as (PDA), and can obtain substantially the same effect as that of a mobile phone.
Further, it may be a notebook personal computer having a transmission function. In the case of a mobile phone, the mobile phone is not limited to a foldable mobile phone, and may be a straight type mobile phone.

In addition, the case where the layered space forming the sound path is formed using the frame-shaped double-sided pressure-sensitive adhesive sheet has been described. For example, a frame-shaped sheet member made of a rubber elastic member is used as a microphone and a front case. A layered space may be formed by interposing them.
Further, a frame-like (angular ring-shaped) rib may be formed to hang from the inner surface side of the front case, and a layered space may be formed in contact with the peripheral edge of the ceiling surface of the microphone. In this case, the pressure may be simply applied by pressing, or may be bonded.
The distance (offset distance) between the microphone sound hole and the transmission case sound hole is not limited to approximately 2 mm, and may be set, for example, within a range of approximately 1 mm to approximately 3 mm.

Further, the dustproof mesh sheet is not limited to nylon, but may be one using other resin fibers such as polyethylene. The dustproof mesh sheet may be a plain weave or a twill weave. Moreover, it may replace with a woven fabric and may arrange | position a nonwoven fabric sheet.
Further, the dust-proof mesh sheet may be arranged so that the side is surrounded by the double-sided pressure-sensitive adhesive sheet for sticking the microphone to the front case without forming the concave portion for storing the dust-proof mesh sheet.

  As an electronic device, in addition to a portable electronic device, in general, it can be applied to an electronic device mounted with a microphone.

It is a front view of the open state which shows the structure of the foldable mobile telephone which is 1st Example of this invention. It is a block diagram which shows the structure of the mobile phone. FIG. 3 is a front view showing a part of a configuration of a main part of the mobile phone. It is sectional drawing along the AA line of FIG. It is an enlarged view which expands and shows the B section of FIG. It is an enlarged view which expands and shows the C section of FIG. It is explanatory drawing for demonstrating the structure of the microphone mounting structure of the mobile phone, Comprising: It is a figure disassembled and shown in each component. It is explanatory drawing for demonstrating the structure of the microphone mounting structure of the mobile phone, Comprising: It is a figure disassembled and shown in each component. It is a figure for demonstrating the function of the microphone mounting structure, Comprising: It is a schematic diagram which shows the relationship between the frequency of transmission voice, and the sound pressure level of transmission voice. It is a figure for demonstrating the function of the microphone mounting structure, Comprising: It is a schematic diagram which shows the relationship between the frequency of transmission voice, and the sound pressure level of transmission voice. It is explanatory drawing for demonstrating the function of the microphone mounting structure. It is sectional drawing which shows the structure of the principal part of the mobile telephone which is 2nd Example of this invention.

Explanation of symbols

1 Mobile phone (electronic equipment)
7 Lower housing (housing)
9 Front case 9a Transmitting case sound hole (first sound collecting hole)
9q Back side (inner surface)
25 Microphone 25a Microphone sound hole (second sound collection hole)
26 Microphone mounting structure 28 Double-sided adhesive sheet 29 Dust-proof mesh sheet (Dust-proof sheet-like member, mesh-like member)
31 Double-sided adhesive sheet 32 Layered space 41 Front case 41a Transmission sound hole (first sound collection hole)

Claims (11)

A microphone mounting structure in which a microphone is mounted in a housing of an electronic device,
The housing is provided with a first sound collection hole, and the microphone has a second sound collection hole, and the second sound collection hole is the first sound collection hole of the housing. Are arranged so as not to overlap the first sound collection hole, and between the inner surface of the housing and the microphone, the first sound collection 2. A microphone mounting structure in an electronic device, wherein a layered space is formed that constitutes a sound path for guiding sound input from a hole to the second sound collecting hole.   The microphone is adhered to an inner surface of the casing by a frame-shaped double-sided pressure-sensitive adhesive sheet, and the layered space is formed so that a side is surrounded by an inner surface of the double-sided pressure-sensitive adhesive sheet. Item 14. A microphone mounting structure in an electronic device according to Item 1.   3. A microphone mounting structure in an electronic apparatus according to claim 1, wherein a dustproof sheet-like member is disposed on the sound path.   The distance between the first sound collection hole and the second sound collection hole and the volume or cross-sectional area of the layered space are set to predetermined values. A microphone mounting structure in the electronic device described.   The microphone mounting structure in an electronic apparatus according to claim 3 or 4, wherein the dust-proof sheet-like member is a mesh-like member made of woven fabric.   6. The microphone mounting structure in an electronic apparatus according to claim 5, wherein the dust-proof sheet-like member is a mesh-like member having a predetermined roughness.   The distance between the first sound collection hole and the second sound collection hole, the volume or cross-sectional area of the layered space, and the mesh roughness of the mesh-like member depend on the frequency characteristics of the transmission level of the microphone. 7. The microphone mounting structure in the electronic device according to claim 6, wherein the microphone mounting structure is set to a predetermined value or type.   8. The electronic apparatus according to claim 4, wherein a distance between the first sound collection hole and the second sound collection hole is set to be approximately 1 mm or more and approximately 3 mm or less. Microphone mounting structure.   9. The microphone mounting structure in an electronic device according to claim 3, wherein the dustproof sheet-like member is subjected to water repellent processing.   The microphone mounting structure in an electronic device according to claim 3, wherein the dust-proof sheet-like member is adhered to the inner surface of the housing by a frame-shaped double-sided adhesive sheet. .   11. An electronic device comprising a microphone mounting structure in the electronic device according to claim 1.

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