JP5255949B2 - Speaker device - Google Patents

Description

  The present invention relates to a speaker device, and particularly uses a flat speaker.

  For example, there are planar speakers disclosed in Patent Documents 1 and 2, and a plane wave that spreads only forward and backward is emitted from a pair of sound emitting surfaces facing backward. In other words, since the sound does not diffuse in the other directions, the attenuation rate is small compared to the sound of a spherical wave from a point sound source, and there is an advantage that the sound can be delivered far away without producing a loud sound. .

Japanese Patent No. 3192372 Japanese Patent No. 3159714

  As described above, a flat speaker has a merit that sound can reach well in the front-rear direction of a pair of sound emitting surfaces. For example, in a space long in the traveling direction of a train, such as in a station premises, the traveling direction It is conceivable to use a flat speaker for announcement purposes. However, since the station is also a crowded space, it is desirable that the speaker is installed at a location that does not obstruct the space as much as possible. As a place satisfying such conditions, it is on an electric bulletin board or attached to a ceiling, and is a high place of 3 m or more. If the flat speaker is installed in such a high place so that the sound emission surface faces in the horizontal direction, the sound will reach the front and rear of the horizontal speaker well, but the sound will reach the ears of the person below the flat speaker. There is a problem that it is difficult.

  Accordingly, the present invention provides a speaker device capable of delivering sound in a specific direction other than the sound emitting direction of the flat speaker while taking advantage of the original merit of the flat speaker, that is, the sound is well delivered in the front-rear direction of the sound emitting surface. The purpose is to provide.

The speaker device of one embodiment of the present invention includes a flat speaker. The planar speaker has a sound emitting surface and emits a plane wave in a direction orthogonal to the sound emitting surface. A derivative is provided at the end of the sound emitting surface. The derivative diffracts a part of the plane wave and guides it in a specific direction other than the orthogonal direction, and projects from the end of the sound emitting surface in the specific direction. As the derivative, a curved one can be used, or a straight one can be used.

In the speaker device configured in this way, a part of the plane wave emitted in the direction orthogonal to the sound emission surface wraps around (that is, diffracts) along the protruding derivative, and is guided in a specific direction from one end of the planar speaker. Is done.
The derivative does not unnecessarily diffuse the energy in the traveling direction of the plane wave, but only guides a part of the emitted plane wave in a specific direction. Sounds can also be delivered in a specific direction.

In particular, the derivative is provided obliquely downward on the lower end side of the flat speaker . For example, in addition to the lower end, the derivative can be provided at the upper end or both ends. However, if the derivative is provided obliquely downward at the lower end, for example, near the ceiling of a building or information on the platform of the station Even when a speaker is arranged, a person lying diagonally below can hear the sound.

  In addition to this, another derivative can also be projected from the upper end portion of the flat speaker in the specific direction. When configured in this way, sound can be guided diagonally downward not only from the lower end but also from the upper end, and even when a flat speaker is placed near the ceiling of the building or above the platform of the station People nearby can hear the sound more clearly.

  As described above, according to the present invention, sound can be diffused and delivered in a specific direction other than the sound emission direction of the flat speaker without unnecessarily diffusing the plane wave.

  As shown in FIG. 2, the speaker device 2 according to the first embodiment of the present invention has a high place, for example, a height of about 3 m, such as a ceiling 4 or an electric bulletin board (not shown) in the station premises. It is attached and used, and has a flat speaker 6 as shown in FIG. The flat speaker 6 is configured, for example, in a flat rectangular parallelepiped shape, and has a pair of sound emitting surfaces 8 and 10 facing back. As indicated by an arrow a in FIG. 1, in the flat speaker 6, the sound is amplified from the sound emitting surfaces 8 and 10 in a direction orthogonal to them. The flat speaker 6 is arranged and attached to a ceiling or the like so that the sound emitting surfaces 8 and 10 are perpendicular to the direction in which sound is to be emitted. The structure of the flat speaker 6 is not described in detail because it is disclosed in the above-mentioned Patent Document 1, but it is a flat speaker having a structure disclosed in Patent Document 2 or a flat speaker having another structure. May be.

  Derivatives 12 and 12 are provided at one end of the flat speaker 6, for example, lower end portions of the sound emitting surfaces 8 and 10, respectively. The derivatives 12 and 12 are provided in the entire lower end portions of the sound emitting surfaces 8 and 10, and are separated from the sound emitting surfaces 8 and 10 in a diagonally downward direction with respect to the lower end portions of the sound emitting surfaces 8 and 10. Accordingly, the sound emitting surfaces 8 and 10 are configured to expand outward. That is, the derivative 12 spreads outside the sound emitting surfaces 8 and 10 in the direction orthogonal to the sound emitting surfaces 8 and 10 as it leaves the sound emitting surfaces 8 and 10. In this embodiment, the derivative 12 is formed symmetrically on each of the sound emitting surfaces 8 and 10 and has a shape curved convexly toward the flat speaker 6 side, that is, upward.

  In the speaker device 2, sound is emitted as a plane wave in a direction orthogonal to the sound emitting surfaces 8 and 10, and a part thereof is diffracted along the protruding derivative 12 as indicated by an arrow b, so as to be inclined downward. Be guided to. Therefore, as shown in FIG. 2, people 14 and 14 who are obliquely below the speaker device 2 can also hear the sound from the flat speaker 6.

  A speaker device 2a according to a second embodiment of the present invention is shown in FIG. The speaker device 2a of this embodiment is the speaker device 2 of the first embodiment, in which the area excluding the lower end portion of the flat speaker 6, that is, the upper end portion and both side end portions are integrally surrounded by the frame body 16. is there. The same parts as those of the speaker device of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Similarly to the speaker device 2, the speaker device 2 a is also mounted at a high place on the premises of the station.

  As shown in FIG. 4, the flat speaker and the figure shown in FIG. 5 without the derivative 12 and the frame body 16 are measured every 10 degrees up to 90 degrees upward with 0 degree directly below the flat speaker 6. FIG. 6 to FIG. 10 show the frequency versus sound pressure characteristics of the third speaker device 2a. 6A is a frequency characteristic diagram at 0 degree, FIG. 6B is a frequency characteristic chart at 10 degrees, FIG. 7A is a frequency characteristic chart at 20 degrees, and FIG. 8A is a frequency characteristic diagram of 40 degrees, FIG. 8B is a frequency characteristic chart of 50 degrees, and FIG. 9A is a frequency characteristic chart of 60 degrees. FIG. 10B is a frequency characteristic diagram of 70 degrees, FIG. 10A is a frequency characteristic chart of 80 degrees, and FIG. 10B is a frequency characteristic chart of 90 degrees. 6 to 10, the frequency characteristic of the speaker device of FIG. 5 is indicated by the symbol α, and the frequency characteristic of the speaker device of FIG. 3 is indicated by the symbol β.

  For example, when attention is paid to 1 KHz, the flat speaker without the derivative 12 and the frame 16 shown in FIG. 5 and the speaker device of FIG. The sound pressure rises to 68 dB and about 69 dB in FIG. 3, and at 20 degrees, the sound pressure further rises to about 72 dB in FIG. 5 and about 74 dB in FIG. At 30 degrees, the sound pressure further increases to about 76 dB in FIG. 5 and about 78 dB in FIG. 3, and at 40 degrees, the sound pressure continues to increase to about 78 dB in FIG. 5 and about 80 dB in FIG. At 50 degrees, it rises to 79 dB in FIG. 5 and 81 dB in FIG. 3, but the growth is moderate. At 60 degrees, the sound pressure rises to 80 dB in FIG. 5 and 82 dB in FIG. 3, but the growth is moderate. At 70 degrees, the elongation is moderate, about 82 dB in FIG. 5 and 83 dB in FIG. At 80 degrees, it is about 82 dB in FIG. 5, about 83 dB in FIG. 3, and at 90 degrees, it is about 83 dB in both FIG. 5 and FIG. The same tendency can be read at other frequencies, and in the range of 10 to 40 degrees, by providing the derivative 12 and the frame body 16, the sound pressure is greatly increased as compared with the case where it is not provided.

  FIG. 11 shows a speaker device 2b according to the third embodiment. In this speaker device 2b, other derivatives 12a and 12a are provided over the entire area of the sound emitting surfaces 8 and 10 at the upper end of the frame 16 of the flat speaker 2a. In this speaker device 2b, the derivatives 12a, 12a are inclined linearly downward toward the lower side so as to form an angle of about 30 degrees with the direction perpendicular to the sound emitting surfaces 8, 10, respectively. Symmetric. Similarly to the speaker devices 2 and 2a, the speaker device 2b is also attached to a high place such as a station premises, and, like the speaker devices 2 and 2a, the sound is emitted as a plane wave in a direction perpendicular to the sound emitting surfaces 8 and 10. A part of the sound is induced by the derivatives 12, 12, 12a and 12a obliquely downward from the lower surface and the upper surface of the sound emitting surfaces 8, 10, respectively.

  In addition, as shown in FIG. 12, the curved derivatives 12b and 12b can be provided instead of the derivative 12a. In this case, the derivatives 12b and 12b are formed in a convex manner toward the lower side opposite to the derivative 12, and are formed symmetrically with each other. Further, without providing the frame body 16a, the derivative 12 can be provided at the lower end of the sound emitting surfaces 8, 10 of the flat speaker 6, and the derivatives 12a, 12a or 12b, 12b can be provided at the upper end.

  In each of the above-described embodiments, the derivatives 12 and 12a are provided on the sound emitting surfaces 8 and 10, respectively, but may be provided only on either one side. Moreover, although the flat speaker 6 used what has the sound-emitting surfaces 8 and 10 facing back, the flat speaker which has only any one sound-emitting surface can also be used. In this case, a derivative may be provided only on the sound emitting surface side.

1 is a perspective view of a speaker device according to a first embodiment of the present invention. It is a figure which shows the attachment state of the speaker apparatus of FIG. It is a perspective view of the speaker apparatus of the 2nd Embodiment of this invention. It is a figure which shows the measurement position of the sound pressure characteristic of the speaker apparatus of FIG.3 and FIG.5. FIG. 2 is a perspective view of a flat speaker in which a derivative is removed from the speaker device of FIG. 1. FIG. 6 is a sound pressure versus frequency characteristic diagram at 0 degrees and 10 degrees of the speaker device of FIGS. 3 and 5. FIG. 6 is a sound pressure versus frequency characteristic diagram at 20 degrees and 30 degrees of the speaker device of FIGS. 3 and 5. FIG. 6 is a sound pressure versus frequency characteristic diagram at 40 degrees and 50 degrees of the speaker device of FIGS. 3 and 5. FIG. 6 is a sound pressure versus frequency characteristic diagram at 60 degrees and 70 degrees of the speaker device of FIGS. 3 and 5. FIG. 6 is a sound pressure versus frequency characteristic diagram at 80 degrees and 90 degrees of the speaker device of FIGS. 3 and 5. It is a perspective view of the speaker apparatus of the 3rd Embodiment of this invention. It is a side view of the modification of the speaker apparatus of FIG.

Explanation of symbols

6 flat speaker 8 10 sound emitting surface 12 derivative 16 frame

Claims (2)

In a speaker device including a flat speaker that has a sound emitting surface and emits a plane wave in a direction orthogonal to the sound emitting surface,
The speaker apparatus which provided the derivative | guide_body which diffracts a part of said plane wave and guide | induces in the specific direction other than the said orthogonal direction in the lower end side of the said plane speaker toward diagonally downward .   The speaker device according to claim 1, wherein another derivative is provided on an upper end side of the flat speaker so as to protrude obliquely downward.

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