JP2006197454A - Loudspeaker system, and portable terminal with it and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lighten, thin, and shorten a loudspeaker while obtaining excellent acoustic characteristics. <P>SOLUTION: A loudspeaker system 100 is composed of an electromechanical acoustic transducer 101 having a diaphragm and emitting a sound by vibrating the diaphragm in response to an electric signal; a first box body 102 with the mounted electromechanical acoustic transducer 101; and a second box body 103 surrounding the electromechanical acoustic transducer 101 and being connected to the first box body 102. The loudspeaker system 100 is further composed of a rear volume 104 formed of the first box body 102 and the second box body 103, a sound-emitting hole 105 formed of the first box body 102 and an acoustic space 107 formed of a side wall member 106 surrounding the sound-emitting hole 105. The acoustic space 107 functions so as to make a frequency lower than the minimum resonance frequency of the electromechanical acoustic transducer 101. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a speaker system, a portable terminal such as a mobile phone equipped with the speaker system, and an electronic device such as a personal computer and a game machine.

  As shown in FIGS. 15A and 15B, the conventional speaker system 1500 has a diaphragm and vibrates the diaphragm according to an electric signal as shown in FIGS. An electromechanical acoustic transducer 1501 for emitting sound, a first housing 1502 to which the electromechanical acoustic transducer 1501 is attached, and a second housing that surrounds the electromechanical acoustic transducer 1501 and is coupled to the first housing 1502. A volume space 1504 formed on the back surface of the electromechanical acoustic transducer 1501 by the first casing 1502, the first casing 1502, and the second casing 1503, and the first casing 1502. The sound emitting hole 1505 and the side wall member 1506 surrounding the sound emitting hole 1505 are provided.

  Here, the side wall member 1506 is generally configured by attaching an elastic body to the periphery of the electromechanical acoustic transducer 1501. In addition to this, the side wall member 1506 projects from the first casing 1502. In some cases, the projecting member may be constituted by a projecting member or a projecting member projecting from the electromechanical acoustic transducer 1501, or both of them may be used.

In any case, since the primary purpose of preventing the deterioration of the sound pressure is a characteristic of these configurations, the first casing 1502 and the electromechanical acoustic transducer 1501 are arranged close to each other. A function as an acoustic tube that resonates the sound emitted from the electromechanical acoustic transducer 1501 in the space 1507 formed by the first casing 1502 and the side wall member 1506 around the sound emission hole. Did not have. That is, it only served as a sound path (hereinafter referred to as “sound path space 1507”).
JP 2001-309007 A JP 2003-152837 A

  However, when a portable terminal or an electronic device is reduced in size and size by using the speaker system having the above-described configuration, there is a problem in that the acoustic characteristics emitted from the sound emission hole 1505 to the outside greatly deteriorate. The reason is considered to be the following phenomenon. That is, in the conventional configuration, in order to reduce the size of the device, it is necessary to reduce the volume space 1504 formed by the first casing 1502 and the second casing 1503. This is a phenomenon in which the electromechanical acoustic transducer 1501 cannot sufficiently resonate and the frequency of the lowest resonance frequency increases.

  Here, FIG. 16 is a correlation diagram showing the correlation of sound pressure-frequency characteristics when the volume of the volume space 1504 is varied in the conventional configuration shown in FIGS. 15 (A) and 15 (B). is there. According to FIG. 16, it can be confirmed that the speaker reproduction band becomes narrower as the volume of the volume space 1504 becomes smaller, and as a result, the problem that the acoustic characteristics deteriorate can be easily inferred.

In general, it is known that the volume space 1504 desirably has a sufficient volume with respect to the resonance of the electromechanical acoustic transducer 1501 in order to obtain good acoustic characteristics. That is, the above-described conventional speaker system has a problem to be solved that it is very difficult to achieve both a light and thin device and good acoustic characteristics.

  Therefore, the present invention has been made to solve the above-described problems in the speaker system having a conventional configuration, and functions as an acoustic tube interposed between the electromechanical acoustic transducer 1501 and the sound emitting hole 1505. By forming an acoustic space, an object is to simultaneously provide both light and thin portable terminals and electronic devices and good acoustic characteristics.

  A speaker system according to the present invention includes an electromechanical acoustic transducer that has a yoke and a diaphragm and emits sound by vibrating the diaphragm in response to an electric signal, a sound emitting hole, and the vibration. A first housing to which the electromechanical acoustic transducer is attached from the side having the plate or the yoke side; and the first housing to surround the electromechanical acoustic transducer from the opposite side of the first housing; A second housing to be coupled and a side wall member configured to surround the sound emitting hole, wherein the first housing and the second housing are disposed on a back surface of the electromechanical acoustic transducer. A side wall member that constitutes a volume space, the sound emitting hole is opened outside the region on the first housing facing the diaphragm provided in the electromechanical acoustic transducer, and the sound emitting hole is surrounded by the side wall member. Sound emitted from the electromechanical acoustic transducer is emitted from the sound emission hole. By configuring an acoustic space that resonates in the space until sound is produced, the acoustic pressure-frequency characteristics are configured to be lower than the lowest resonance frequency of the electromechanical acoustic transducer. .

  Moreover, the portable terminal concerning this invention is equipped with the above-mentioned speaker system, It is characterized by the above-mentioned.

  In addition, an electronic device according to the present invention includes the above-described speaker system.

  The portable terminal according to the present invention is also characterized in that the electromechanical acoustic transducer operates as a receiver when the electrical signal is an electrical signal converted from a received sound, and the speaker system is used as a receiver. Even when operated, it is possible to obtain a sound effect peculiar to the present invention.

  According to the present invention, by forming an acoustic space that functions as an acoustic tube between the electromechanical acoustic transducer and the sound emitting hole, the portable terminal and the electronic device can be reduced in size and thickness and have good acoustic characteristics. Both can be provided at the same time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  (Embodiment 1) A speaker system 100 according to Embodiment 1 of the present invention will be described with reference to FIG. 1A is a top view of the speaker system 100, FIG. 1B is a cross-sectional view taken along the chain line AA ′ in FIG. 1A, and FIG. 1C is FIG. It is sectional drawing along the dashed-dotted line BB 'in FIG. FIG. 1D is a perspective view showing how the speaker system 100 is incorporated.

The speaker system 100 includes a diaphragm, an electromechanical acoustic transducer 101 that emits sound by vibrating the diaphragm according to an electrical signal, and a first housing 102 to which the electromechanical acoustic transducer 101 is attached. A second surrounding the electromechanical acoustic transducer 101 and coupled to the first housing 102
, The volume space 104 formed by the first housing 102 and the second housing 103, the sound emitting hole 105 formed in the first housing 102, and the sound emitting hole 105. And an acoustic space 107 that functions as an acoustic tube and is formed by a side wall member 106 attached to the first housing 102 so as to surround the housing.

  Here, the acoustic space 107 is formed so that the first housing 102 and the electromechanical acoustic transducer 101 cover the side wall member 106. In other words, the acoustic space 107 is formed by covering the side wall member 106 so as to cover the gap formed by the first housing 102 and the electroacoustic transducer 101 facing each other. . Therefore, the acoustic space 107 is a space different from the sound path space 1507 formed by the first casing 1502, the electromechanical acoustic transducer 1501, and the side wall member 1506 in FIG.

  As a structural feature for forming such an acoustic space 107 different from the sound passage space, as shown in FIG. 1C, the opening position of the sound emitting hole 105 is set to the first housing 102. It is mentioned that it exists out of the area | region facing the upper electromechanical acoustic transducer 101. FIG. In addition, this feature is that when the upper portion of the speaker system 100 as shown in FIG. 1A is also viewed, the sound emitting hole 105 is connected to the electromechanical acoustic transducer 101 on the first housing 102. It is possible to clearly see the state of being provided outside the circular regions facing each other.

  As described above, the acoustic space 107 is structurally different from the conventional sound path space by first opening the sound emitting hole 105 at a position appropriately separated from the electromechanical acoustic transducer 101. It is mentioned that a space is formed. As for the significance of the opening position of the sound emitting hole 105 (why it is necessary to open the sound emitting hole 105 at a position away from the electromechanical acoustic transducer 101), the current technical trend of the speaker system has become lighter. It can be mentioned that there is a background that is going on. In other words, since the acoustic space 107 must be formed in the speaker system 100 having a very limited thickness limit, the space is just left and right in the cross-sectional view of the speaker system shown in FIG. It is a mechanical request that it is necessary to secure. Here, the acoustic space is desirably a closed space as much as possible. For example, when the side wall member 106 is attached to the first casing 102 or the electromechanical acoustic transducer 101, an adhesive double-sided tape or the like is used. It is preferable to use it.

Next, as a second feature, due to the structure of the acoustic space 107, a part of the outer periphery of the electromechanical acoustic transducer 101 is protruded. This is because it is desirable to have a certain volume. In this state, when viewing FIG. 1A, the side wall member 106 for forming the acoustic space 107 is attached so as to protrude from the outer periphery of the circular electromechanical acoustic device 101 into a rectangular shape. It can be clearly seen as a state of being.
Further, as a third feature, the width of the protruding portion in the AA ′ direction of the rectangular side wall member 106 that appears to protrude in FIG. It can be mentioned that the acoustic device 101 is formed to have the same diameter or narrower than the diameter. The inventor has experimentally found that this structural feature also contributes to the improvement of acoustic characteristics, as will be described later.

  The material of the side wall member 106 is not limited to a specific material / material, but is preferably formed of an elastic body such as urethane foam rubber or a resin.

FIG. 2 is a cross-sectional view of the electromechanical acoustic transducer 101. The electroacoustic transducer 101 according to the embodiment of the present invention is a dynamic speaker.
The electromechanical acoustic transducer 101 includes a saddle-shaped yoke 202, a magnet 203 provided in the center of the yoke 202, a plate 204 provided on the top of the magnet 203, and a magnetic force between the yoke 202 and the plate 204. A voice coil 205 inserted into the gap and a diaphragm 206 connected to the voice coil 205 are provided. The yoke is provided at the center of the housing 207. The housing 207 is attached so that the diaphragm 206 and the housing 207 face each other.

  The operation of the speaker system 100 incorporating the electromechanical acoustic transducer 101 configured as described above will be described. First, an electric signal is applied to the voice coil 205 inserted into the magnetic gap, and a driving force is generated in the voice coil 205. The diaphragm 206 connected to the voice coil 205 generates vibration, and the diaphragm 206 causes a pressure change in the air. A sound is generated by releasing the air pressure thus generated into the space through the sound emission hole 105.

  Next, the effect of providing the acoustic space 107 will be considered using numerical analysis.

  FIG. 3 is a numerical analysis of the correlation between volume space (referred to as “rear volume” in the chart) and speaker system minimum resonance frequency characteristics in the speaker system 1500 having the conventional configuration and the speaker system 100 according to the embodiment of the present invention. It is a correlation diagram shown as a result. Note that the specific numerical values shown below are numerical values set for quantitatively grasping the effects of the present invention, and the numerical values themselves are examples, and these individual numerical values are not restricted to the essence of the present invention. I refuse to do anything.

  In FIG. 3, a dynamic speaker having a diameter of 14 mm and a minimum resonance frequency of 900 Hz is used as the electromechanical acoustic transducer 1501 having the conventional configuration and the electromechanical acoustic transducer 101 according to the embodiment of the present invention. The size of the sound passage space 1507 including the first casing around the sound emission hole and the side wall member surrounding the sound emission hole in the speaker system 1500 having the conventional configuration is such that the diameter φ0 is 11 mm and the depth H0 is 0. The shape size of the acoustic space 107 in the speaker system 100 according to the embodiment of the present invention is 10 mm and the depth H1 is 0.5 mm. The depth D1 is 7.0 mm. Then, microphones of the same model are installed at positions 0.1 m away from the speaker systems 1500 and 100, respectively, with respect to the electromechanical acoustic transducer 1501 having the conventional configuration and the electromechanical acoustic transducer 101 of the present embodiment. Both are set to apply a power of 0.2 W. In addition, in order to clarify the significance of the embodiment of the present invention, numerical analysis results in the case where the electromechanical acoustic transducer 1501 having the conventional configuration is a dynamic speaker having a minimum resonance frequency of 600 Hz are also shown.

  The characteristic I shown in FIG. 3 is a result when the electromechanical acoustic transducer 1501 having the conventional configuration has a minimum resonance frequency of 900 Hz. The characteristic II is a result when the electromechanical acoustic transducer 1501 having the conventional configuration has a minimum resonance frequency of 600 Hz. The characteristic III is a result when the electromechanical acoustic transducer 101 of the embodiment of the present invention has a minimum resonance frequency of 900 Hz.

  Consideration of the significance in the acoustic characteristics of the embodiment of the present invention includes the following two.

  The first significance is the significance of the acoustic space in the expandability of the speaker reproduction band. That is, the volume space 1504 of the conventional configuration that is necessary and sufficient for the resonance of the electromechanical acoustic transducer 1501 having the conventional configuration and the electromechanical acoustic transducer 101 of the present embodiment, and the volume space 104 of the present embodiment. Although the minimum resonance frequency of the electromechanical acoustic transducer 1501 of the conventional configuration and the electromechanical acoustic transducer 101 of the present embodiment is the same 900 Hz, due to the difference between the characteristic I and characteristic III at 45 cc, The lowest resonance frequency of the speaker system 100 according to the embodiment of the present invention is lowered to 600 Hz, and the speaker reproduction band can be expanded.

  The second significance is the significance of the acoustic space for reducing the dependence on the narrowing of the volume space. That is, due to the difference between characteristic II and characteristic III in FIG. 3, the lowest resonance frequency of the speaker system 1500 of the conventional configuration and the speaker system 100 of the embodiment of the present invention is the same 600 Hz, but the volume space 1504 of the conventional configuration. As the volume space 104 of the embodiment of the present invention is reduced, the lowest resonance frequency of the speaker system 1500 having the conventional configuration is remarkably increased. On the other hand, the speaker system 100 according to the embodiment of the present invention is gentler than the speaker system 1500 having the conventional configuration. In particular, the volume space of recent light and thin devices is about 1 cc, and the significant difference in the minimum resonance frequency in this volume space is obvious. Further, due to the difference between the characteristic I and the characteristic II, the volume space 1504 of the conventional configuration is about 1 cc, although there is a difference between 900 Hz and 600 Hz at the lowest resonance frequency of the electromechanical acoustic transducer 1501 of the conventional configuration. The original significance is almost gone.

  FIG. 4 is a correlation diagram showing the result of numerical analysis of the significance of the embodiment of the present invention described above as the state of correlation of sound pressure-frequency characteristics. Note that the specific numerical values shown below are numerical values set for quantitatively grasping the effects of the present invention, and the numerical values themselves are examples, and these individual numerical values are not restricted to the essence of the present invention. I refuse to do anything.

  In the numerical analysis of FIG. 4, both the conventional volume space 1504 and the volume space 104 of the present embodiment are 1 cc, the electromechanical acoustic transducer 1501 of the conventional structure and the electromechanical sound of the present embodiment. Both the converter 101 uses a dynamic speaker having a diameter of 14 mm and a minimum resonance frequency of 900 Hz. Also, the size of the sound passage space constituted by the first casing around the sound emitting hole and the side wall member surrounding the sound emitting hole in the speaker system 1500 having the conventional configuration is such that the diameter φ0 is 11 mm and the depth H0 is 0.1. Whereas the size of the acoustic space in the speaker system 100 according to the embodiment of the present invention is 5 mm, the diameter φ1 is 10 mm and the depth H1 is 0.5 mm. The depth D1 of the acoustic space peculiar to the present invention. Is 7.0 mm. Then, microphones of the same model are installed at positions 0.1 m away from the speaker systems 1500 and 100, and both the electromechanical acoustic transducer 1501 having the conventional configuration and the electromechanical acoustic transducer 101 of the present embodiment are 0. .2 W power is applied. In addition, in order to clarify the significance of the embodiment of the present invention, numerical analysis results in which the volume space 1504 of the conventional configuration is 10 cc are also shown.

  This is a result of the characteristic IV shown in FIG. 4 and the conventional configuration of the volume space 1504 of 1 cc. The characteristic V is a result of the volume space 104 of the embodiment of the present invention being 1 cc. Characteristic VI is a result of the conventional configuration of the volume space 1504 of 10 cc.

  The following two points can be mentioned to consider the significance of the thinning and thinning of the embodiment of the present invention.

  The first significance is that the significance is seen in the speaker reproduction band in the same volume space (1 cc). That is, from the difference from the characteristic IV characteristic V, the lowest resonance frequency of the speaker system 1500 having the conventional configuration is 1300 Hz, and the lowest resonance frequency of the speaker system 100 according to the embodiment of the present invention is 850 Hz. Significant difference has occurred.

  The second significance is the significance of the volume space when obtaining the same speaker reproduction band. In other words, due to the difference between the characteristic V and the characteristic VI, in order to make the volume space 104 of the embodiment of the present invention the same frequency as the lowest resonance frequency of the speaker system 100 at 1 cc, the conventional configuration requires about 10 cc of the volume space 1504. It becomes. That is, even if the same speaker reproduction band is realized, the embodiment of the present invention is more significant for lighter, thinner and smaller than the conventional configuration.

  As described above, it can be seen that the speaker system 100 according to the embodiment of the present invention has the above-described significance with respect to the conventional configuration by having the acoustic space 107 having its unique structure.

  Note that the position of the sound emitting hole 105 in the embodiment of the present invention is not limited to the opening position as long as the effect unique to the present invention is not lost.

  For example, in the embodiment of the present invention, the diaphragm side of the electroacoustic transducer 101 is mounted on the first housing 102, and the electromechanical acoustic transducer 101 and the sound emitting hole 105 are arranged to face each other. However, for example, as in the example shown in FIG. 5, the electromechanical acoustic transducer 501 and the sound emission hole 505 do not face each other, and the sound emission hole 505 is disposed on the side surface of the first housing 502. Good. 5A is a top view of the speaker system 500, FIG. 5B is a cross-sectional view taken along the chain line AA ′ shown in FIG. 5A, and FIG. It is sectional drawing along the dashed-dotted line BB 'shown to 5 (A).

  In addition, the yoke side of the electroacoustic transducer 601 is mounted on the first housing 602, and the electromechanical acoustic transducer 601 and the sound emitting hole 605 are not opposed to each other and are released to the side surface of the first housing 601. A sound hole 605 may be disposed. 6A is a top view of the speaker system 600, FIG. 6B is a cross-sectional view taken along the chain line AA ′ shown in FIG. 6A, and FIG. 6 is a cross-sectional view taken along a chain line BB ′ shown in FIG.

  Further, the yoke side of the electroacoustic transducer 701 is mounted on the first housing 702, and the sound emitting hole is formed in the first housing 702 so that the electromechanical acoustic transducer 701 and the sound emitting hole 705 are opposed to each other. 705 may be arranged. 7A is a top view of the speaker system 700, FIG. 7B is a cross-sectional view taken along the chain line AA ′ shown in FIG. 7A, and FIG. 7 is a cross-sectional view taken along a chain line BB ′ shown in FIG.

  Note that a plurality of sound emitting holes 105 in the embodiment of the present invention can be arranged in the first housing 102.

  In the embodiment of the present invention, the diaphragm side of the electroacoustic transducer 101 is mounted on the first housing 102, and the electromechanical acoustic transducer 102 and the sound emitting hole 105 are opposed to each other, so that the sound emitting hole 105 is provided. However, for example, a plurality of sound emitting holes 805 may be arranged as in the case shown in FIG. 8A is a top view of the speaker system 800, FIG. 8B is a cross-sectional view taken along the chain line AA ′ shown in FIG. 8A, and FIG. It is sectional drawing which followed the dashed-dotted line BB 'shown to 8 (A).

  (Embodiment 2) A speaker system 900 according to Embodiment 2 of the present invention will be described with reference to FIGS. 9 (A), 9 (B) and 9 (C). Here, FIG. 9A is a top view of the speaker system 900, FIG. 9B is a cross-sectional view along the chain line AA ′ shown in FIG. 9A, and FIG. FIG. 10 is a cross-sectional view taken along the chain line BB ′ shown in FIG. In the embodiment of the present invention, a side wall member 906 constituting an acoustic space is formed by the side wall member 906 and a projecting portion projecting from the first housing 902 with respect to the first embodiment. Yes. The operation of the speaker system 900 is the same as that of the speaker system 100 described in the first embodiment.

(Embodiment 3) A speaker system 1000 according to Embodiment 3 of the present invention will be described with reference to FIGS. 10A, 10B, and 10C. Here, FIG. 10A is a top view of the speaker system 1000, and FIG. 10B is a chain line A- shown in FIG.
FIG. 10C is a cross-sectional view taken along the chain line BB ′ shown in FIG. 10A. In the embodiment of the present invention, the side wall member 1006 constituting the acoustic space is formed by the side wall portion 1006 material and the projecting portion projecting from the electromechanical acoustic transducer 1001 with respect to the first embodiment. ing. The operation of the speaker system 1000 is the same as that of the speaker system 100 described in the first embodiment.

  (Embodiment 4) A speaker system 1100 according to Embodiment 4 of the present invention will be described with reference to FIGS. 11 (A), 11 (B), and 11 (C). Here, FIG. 11A is a top view of the speaker system 1100, FIG. 11B is a cross-sectional view along the chain line AA ′ shown in FIG. 11A, and FIG. FIG. 12 is a cross-sectional view taken along the chain line BB ′ shown in FIG. In the embodiment of the present invention, the side wall member 1106 constituting the acoustic space with respect to the first embodiment includes the side wall member 1106, a projecting portion projecting from the first housing 1102, and the electric machine. It is formed by a projecting portion projecting from the acoustic transducer 1101. The operation of the speaker system 1100 is the same as that of the speaker system 100 described in the first embodiment.

  (Embodiment 5) A speaker system 1200 according to Embodiment 5 of the present invention will be described with reference to FIGS. 12 (A), 12 (B), and 12 (C). Here, FIG. 12A is a top view of the speaker system 1200, FIG. 12B is a cross-sectional view along the chain line AA ′ shown in FIG. 12A, and FIG. FIG. 13 is a cross-sectional view taken along the chain line BB ′ shown in FIG. The embodiment of the present invention includes a plurality of electromechanical acoustic transducers 1201, side wall members 1206 constituting a plurality of acoustic spaces, and a plurality of sound emitting holes 1205. Each of the plurality of electromechanical acoustic transducers 1201 includes The side wall member 1206 that has a diaphragm and generates a sound by vibrating the diaphragm in accordance with an electrical signal and forms a plurality of acoustic spaces is provided with a sound from each of the plurality of sound emission holes 1205. And a sound emitting hole 1205 for emitting sound. Note that the operation of the speaker system 1200 is the same as that of the speaker system 100 described in the first embodiment.

  (Embodiment 6) A portable terminal 1300 according to Embodiment 6 of the present invention will be described with reference to FIG. In the embodiment of the present invention, the mobile terminal 1300 is described as a mobile phone. However, the present invention is not limited to this embodiment. For example, a PDA (Personal Digital Assistant), a pager (registered trademark), or the like may be used. Good. First, the mobile terminal 1300 includes a lower housing 1303 containing a receiving circuit 1302 and the like, a receiving antenna 1304 attached to the lower housing 1303, a signal output unit 1305 that amplifies an electric signal, a connector, and the like (not shown). ). The portable terminal 1300 includes an upper housing 1306 that supports the speaker system 1301. The speaker system 1301 includes a diaphragm, and emits sound by vibrating the diaphragm according to an electric signal. An acoustic transducer; a first housing to which the electromechanical acoustic transducer is attached; a second housing that surrounds the electromechanical acoustic transducer and is coupled to the first housing; and a first housing; A volume space formed by the second housing, a sound emitting hole formed in the first housing, and an acoustic space formed by a side wall member surrounding the sound emitting hole, and the acoustic space Is configured to be able to lower the frequency below the lowest resonance frequency of the electromechanical acoustic transducer.

Next, the operation of the mobile terminal 1300 will be described. The operation of the speaker system 1301 is the same as that of the speaker system 100 described in the first embodiment. That is, when an electric signal indicating a received sound is applied to the speaker system 1301, the received sound is reproduced from the sound emission hole. In this case, the speaker system 1301 functions as a receiver that is a speaker for reproducing the received sound. Further, if an electric signal indicating a ring tone, music, voice or game sound effect for notifying an incoming call is applied to the speaker system 1301, the ring tone, music, voice or sound effect is reproduced from the sound output hole. In this case, the speaker system 1301 functions as a loudspeaker speaker. Note that the first housing may also serve as the upper housing 1306 of the mobile terminal 1300, and the second housing may also serve as the upper housing 1306 of the mobile terminal 1300.

  (Embodiment 7) An electronic apparatus 1400 according to Embodiment 7 of the present invention will be described with reference to FIG. In the embodiment of the present invention, the electronic device 1400 is described as a notebook personal computer. However, the present invention is not limited to this. For example, the electronic device 1400 may be a stationary electronic device or a desktop personal computer. First, the electronic device 1400 includes an upper housing 1403 that incorporates a speaker system 1401 and a display device 1402, a signal output unit 1405 that amplifies an electric signal based on a control unit 1404 in conjunction with a user operation, a CPU, a memory, and the like. An electronic apparatus 1400 including a lower housing 1406 (not shown), in which a speaker system 1401 has a diaphragm and emits sound by vibrating the diaphragm in response to an electrical signal. An electromechanical acoustic transducer, a first housing to which the electromechanical acoustic transducer is attached, a second housing that surrounds the electromechanical acoustic transducer and is coupled to the first housing; A volume space formed by a housing and a second housing; a sound emitting hole formed in the first housing; and an acoustic space formed by a side wall member surrounding the sound emitting hole, Acoustic space Configured to be lowered frequency than the minimum resonance frequency of the electromechanical acoustic transducer.

  Next, the operation of the electronic device 1400 will be described. The operation of the speaker system 1401 is the same as that of the speaker system 100 described in the first embodiment. That is, the speaker system 1401 is amplified by the signal output unit 1402 that amplifies the electric signal based on the control unit 1402 in conjunction with a user operation, and the electric signal is applied to the speaker system 1401 and reproduced. Note that the first housing may also serve as the mobile terminal housing 1404, and the second housing may serve as the mobile terminal housing 1404.

  As described above, the speaker system according to the present invention includes at least a diaphragm, and includes an electromechanical acoustic transducer that emits sound by vibrating the diaphragm according to an electrical signal, and the electromechanical acoustic transducer. A first casing to be attached, a second casing surrounding the electromechanical acoustic transducer and coupled to the first casing, and the first casing and the second casing are formed. A volume space, a sound emitting hole formed in the first housing, and an acoustic space formed by a side wall member surrounding the sound emitting hole are provided. And since the said acoustic space is comprised so that a frequency can be lowered | hung below the lowest resonance frequency of the said electromechanical acoustic transducer, while obtaining the favorable acoustic characteristic, at the same time implement | achieving the lightness and thinness of the apparatus which has a speaker system. Can do. Furthermore, the speaker system according to the present invention can be widely applied not only as a portable terminal such as a mobile phone but also as a speaker system in electronic devices such as personal computers and game machines.

Structure diagram showing the structure of the speaker system according to Embodiment 1 of the present invention. Sectional drawing which shows the cross section of the electromechanical acoustic transducer in Embodiment 1 of this invention The correlation diagram which shows the correlation with the volume space (back surface volume) and the minimum resonance frequency characteristic in the speaker system concerning this invention Correlation diagram showing the correlation between sound pressure and frequency characteristics in the speaker system according to the present invention. Structural diagram showing another structure of the speaker system according to Embodiment 1 of the present invention. Structural diagram showing another structure of the speaker system according to Embodiment 1 of the present invention. Structural diagram showing another structure of the speaker system according to Embodiment 1 of the present invention. Structural diagram showing another structure of the speaker system according to Embodiment 1 of the present invention. Structural diagram showing the structure of the speaker system according to Embodiment 2 of the present invention. Structural diagram showing the structure of the speaker system according to Embodiment 3 of the present invention. Structure diagram showing the structure of the speaker system in Embodiment 4 of the present invention Structure diagram showing the structure of the speaker system in Embodiment 5 of the present invention The block diagram which shows the structure of the portable terminal in Embodiment 6 of this invention. The block diagram which shows the structure of the electronic device in Embodiment 7 of this invention Structural diagram showing the structure of a conventional speaker system Correlation diagram showing the correlation between sound pressure and frequency characteristics for volume changes

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Speaker system 101 Electromechanical acoustic transducer 102 1st housing | casing 103 2nd housing | casing 104 Volume space 105 Sound emitting hole 106 Side wall member 107 Acoustic space 1507 Sound passage space

Claims (7)

An electromechanical acoustic transducer having a yoke and a diaphragm and emitting sound by vibrating the diaphragm in response to an electrical signal;
A first housing having a sound emitting hole and mounting the electromechanical acoustic transducer from the side having the diaphragm;
A second housing coupled to the first housing so as to surround the electromechanical acoustic transducer from the opposite side of the first housing;
A side wall member configured to surround the sound emitting hole,
The first casing and the second casing constitute a volume space on the back surface of the electromechanical acoustic transducer, and the sound emitting hole faces the diaphragm provided in the electromechanical acoustic transducer. The side wall member that opens outside the region on the housing 1 and surrounds the sound emitting hole resonates in the space until the sound emitted from the electromechanical acoustic transducer is emitted from the sound emitting hole. A loudspeaker system characterized in that a sound space is configured to be lower than a lowest resonance frequency of the electromechanical acoustic transducer in a sound pressure-frequency characteristic by configuring a sound space. The speaker system according to claim 1, wherein the electromechanical acoustic transducer is attached to the first casing from the side having the yoke. The speaker system according to claim 1 or 2, wherein the acoustic space is formed by the side wall member and a projecting portion projecting from the first casing. The speaker system according to claim 1, wherein the acoustic space is formed by the side wall member and a projecting portion projecting from the electromechanical acoustic transducer. A portable terminal comprising the speaker system according to any one of claims 1 to 4. An electronic apparatus comprising the speaker system according to any one of claims 1 to 4. 6. The portable terminal according to claim 5, wherein the electric signal is an electric signal converted from a received sound, and the electromechanical acoustic transducer operates as a receiver.

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