Sound output device

Abstract

To provide a sound output device that can maintain frequency resolution and directivity without increasing the number of speakers. [Solution] The sound output device (100) comprises a speaker (10) and a plurality of sound conduits (20) that guide the sound output by the speaker (10). The plurality of sound conduits (20) have different path lengths from the sound input end to the output end. The sound output range of the sound output device (100) may be determined based on the arrangement of the output ends and the difference in sound output timing from the output ends according to the path length.

Description

Technical Field

[0001] This invention relates to a sound output device.

Background Art

[0002] There is a technique of using a plurality of speakers to give directivity to the sound output direction by adding the outputs from the plurality of speakers or locally enhancing the sound within a specific output range. Patent Document 1 discloses a technique regarding a tangent method of adjusting the sound output timing from a speaker array to align the phases of the output sounds on an arc and cancel out the sounds of each speaker outside the arc.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in order to obtain good directivity while maintaining the frequency resolution of the sound, it is necessary to increase the number of speakers.

[0005] An object of this invention is to provide a sound output device capable of maintaining frequency resolution and directivity without increasing the number of speakers.

Means for Solving the Problems

[0006] To achieve the above object, this invention includes a speaker, a plurality of sound guide tubes for guiding the sound output from the speaker, and is provided with wherein the plurality of sound guide tubes have different path lengths from the sound incident end to the sound exit end, and is a sound output device.

Effects of the Invention

[0007] According to the present invention, a sound output device can maintain frequency resolution and directivity without increasing the number of speakers. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram illustrating the sound output device of this embodiment. [Figure 2] This is a perspective view of the pronunciation section. [Figure 3] This is a plan view of the sound-producing section. [Figure 4] This is a cross-sectional perspective view of a sound conduit. [Figure 5] This is a schematic diagram illustrating the direction of sound output. [Figure 6] This is a plan view showing the sound-producing section of another embodiment. [Figure 7] This is a cross-sectional view showing the sound-producing section of another embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. The sound output device 100 of this embodiment comprises a plurality of sound-producing units 1 and a housing 2, as shown in Figure 1. The sound-producing units 1 emit sound using a speaker 10 (see Figure 2), as described later. The housing 2 fixes and supports the sound-producing units 1 and has signal wiring that sends electrical signals input to connection terminals (not shown) to each sound-producing unit 1. The sound-producing units 1 may be arranged in a straight line.

[0010] As shown in the perspective view of Figure 2, one sound-producing unit 1 has a sound conduit 20 located on the sound emission side (+z side) of the speaker 10. The speaker 10 is equipped with a diaphragm 11 that converts voltage into vibration. Sound is produced when the air vibrates due to the vibration of the diaphragm 11. The diaphragm 11 may be a plate-like structure that is thicker than a typical membrane, as long as it can produce sound with an appropriate amplitude.

[0011] Sound, which is the vibration of air generated by speaker 10, is incident on the sound conduit 20 from the incident end 201 (see Figure 4) located on the -z side and output from the exit end 202 (see Figure 4) located on the +z side. Multiple sound conduits 20 are located for a single speaker. Here, five sound conduits 20a to 20e are arranged in a line in the x direction. For example, the sound conduit 20 may be a thin, flat plate in the x direction.

[0012] As shown in the plan view of Figure 3, the five sound conduits 20a to 20e are located on the diaphragm 11 in a plan view, and the sound generated by the vibration of the diaphragm 11 directly enters the interior of the sound conduits 20a to 20e. The sound that enters the interior of the sound conduits 20a to 20e is guided to travel through the interior of the sound conduits 20a to 20e and be output parallel to the +z direction from the output end. Note that the output ends of the sound conduits 20a to 20e do not have to open in the +z direction. For example, they may open in the +y direction. In other words, the direction of sound output due to the vibration of the diaphragm 11 and the direction of sound output from the output ends of the sound conduits 20a to 20e may be different.

[0013] At this time, the output timing from the exit end 202 of the sound simultaneously incident on the sound conduits 20a to 20e is made different from each other, and the sound output range (listening point) obtained by superimposing the output sounds from the multiple sound conduits 20a to 20e is determined. As shown in Figure 4, which is a perspective view of the cross section along the cross section line AA in Figure 3, the path inside the sound conduit 20 is meandering. Therefore, the path length through which sound travels within the sound conduit 20 is long compared to the external size of the sound conduit 20. The sound output timing is delayed according to the number of meanders, i.e., the path length. The sound conduit 20 may have a structure that is symmetrical on the ±x side with respect to the cross section.

[0014] The sound conduit 20 may have protruding portions 21 that project inward from both walls in the y-direction. Sound entering from the input end 201 meanders around these protruding portions 21 before being emitted from the output end 202. Therefore, the path length of the sound conduit 20 is longer than the length of the sound conduit 20 in the z-direction by the amount that it bends around the protruding portions 21 three times.

[0015] That is, in the sound guide tubes 20a to 20e, the path lengths, for example, the number of protruding portions 21 are different from each other, so that the sound emission timings are different from each other. The output range of the sound is determined by the arrangement of the emission ends 202 of the respective sound guide tubes 20a to 20e and the difference in the emission timings. For example, when the number of protruding portions 21 increases in the order of the sound guide tubes 20a to 20e arranged in the x direction, the wavefront corresponding to the same phase is inclined in the x direction, and the sound is linearly output to the range along the direction bent in the x direction with respect to the z direction. The shapes of the protruding portions 21 may all be the same. By using the required number of components forming the protruding portions 21, the commonization of components and the simplification of the structure can be achieved.

[0016] Alternatively, a part of the protruding portions 21, for example, the protruding portion 21 closest to the emission end 202 may have a shorter protruding length than the other protruding portions 21. It is possible to make it easier for the sound to be output from the emission end 202 in a direction perpendicular to the opening surface of the emission end 202. Further, by setting the lengths of the protruding portions 21 respectively, the setting of the path length by the number of the protruding portions 21 can be performed more finely.

[0017] As schematically shown in FIG. 5, the path lengths in the five sound guide tubes 20a to 20e arranged in a row in the x direction, that is, the number of protruding portions 21 may change one by one in order. In FIG. 5, in order to clearly show the number of protruding portions 21, the direction of the sound guide tube 20 is shown by rotating it 90 degrees with respect to FIG. 2 above. The sound is emitted from the sound guide tube 20a with the fewest protruding portions 21 first, and the sound emission timing is delayed as the number of protruding portions 21 increases. As a result, the sound is output inclined toward the +x side with respect to the z direction. In other directions, the sounds emitted with different phases by the plurality of sound guide tubes 20a to 20e cancel each other out, and the output sound is attenuated. That is, this sound emitting portion 1 may operate as a delay sum beamformer in which the sound output timing is determined structurally.

[0018] When the path lengths of the individual sound guide tubes 20 can be determined finely as described above, the change in the path length for each sound guide tube may be non-linear. In this case, for example, an acoustic beam may be generated along an arc according to the tangent method.

[0019] The sound output device 100 may have a single sound generation unit 1, but as shown in FIG. 1, a plurality of sound generation units 1 each having a speaker 10 may be arranged side by side. In this case, the sound output timings from the plurality of speakers 10 may involve a time difference. That is, the sound incident on the sound conduits 20 corresponding to each speaker 10 with a time difference further causes a difference in output timing according to the path lengths of the plurality of sound conduits 20 respectively. That is, the delay time related to the sound output is represented by the sum of the difference in the output timing of the speaker 10 and the difference in the path lengths of the sound conduits 20. By appropriately determining this delay time for each sound conduit 20, the sound output range by the plurality of sound conduits 20 of the plurality of sound generation units 1 can be determined more accurately. In this case, the set of path lengths of the plurality of sound conduits 20 connected to each speaker 10 may be the same among the sound generation units 1. Since it is sufficient to manufacture a plurality of the same sound generation units 1, the manufacturing cost and labor are reduced. The sound output timing from the speaker 10 may be determined by a processing device that outputs a signal to the speaker 10.

[0020] In addition, in FIG. 1 above, in consideration of the sound resolution and the like, the sound conduits 20a to 20e of the plurality of sound generation units 1 may be designed to be arranged at equal intervals. In this case, the outer edge of the speaker may be narrowly defined so that the incident ends 201 of each of the sound conduits 20a to 20e do not deviate from the plan view range of the diaphragm 11, and the shape of the diaphragm 11 may be appropriately defined, such as square. Alternatively, the path through which the sound travels in the sound conduits 20a to 20e may extend obliquely within the xz plane. That is, in plan view, the positions of the incident end 201 and the exit end 202 may not coincide.

[0021] As shown in Figure 6(a), in the sound-producing unit 1A of one embodiment, the sound conduits 20A may be arranged two-dimensionally on the diaphragm 11A in a plan view. The sound conduits 20A may be approximately square in a plan view to facilitate two-dimensional arrangement. Alternatively, the sound conduits 20A may be circular, elliptical, polygonal, etc., in a plan view. Furthermore, the diaphragm 11A and the speaker 10A having the diaphragm 11A may have roughly the same width in the x and y directions. The diaphragm 11A may have a rounded corner shape or a circular shape. In this case, the protruding portion 21 does not have to be a one-dimensional structure. For example, the sound conduit 20A may have a helical protruding portion 21. Sound may be transmitted along the helical path from the incident end 201 to the exit end 202.

[0022] As shown in Figure 6(b), the sound conduit 20B may be positioned to overlap with the circular diaphragm 11B in a plan view. If the diaphragm 11B includes a portion that does not overlap with the sound conduit 20B, the portion of the speaker 10B other than the sound conduit 20B may be covered with soundproofing material or the like to prevent sound from leaking directly to the outside from the diaphragm 11B.

[0023] Alternatively, if it is difficult to extend the sound conduit in the z direction, the sound path may be located along the xy plane. The cross-sectional view along the xy plane in Figure 7(a) shows a cross-section along the cross-sectional line CC in Figure 7(b), and the cross-sectional view along the yz plane in Figure 7(b) shows a cross-section along the cross-sectional line BB in Figure 7(a). In the sound conduit 20C shown in Figure 7(a), the protruding portion 21 extends in the x direction within the xy plane relative to the path extending in the +y direction from the incident end 201 located on the -y side. As a result, the path meanders within the xy plane. In this case, the exit end 202 of the sound conduit 20C does not need to overlap with the area of ​​the diaphragm 11 in a plan view.

[0024] As shown in Figure 7(b), the incident end 201 is located on the -z side at the -y end of the sound conduit 20C, which extends along the xy plane. The exit end 202 is located on the +z side at the +y end of the sound conduit 20C. By ensuring that the height of the sound conduit 20C in the z direction is within the range necessary for sound propagation, the sound-producing section 1 can be kept thin.

[0025] As described above, the sound output device 100 of this embodiment comprises a speaker 10 and a plurality of sound conduits 20 that guide the sound output by the speaker 10. The plurality of sound conduits 20 have different path lengths from the sound input end 201 to the output end 202. In this way, instead of controlling the amount of sound delay solely with the speaker 10, sound directivity can be obtained by connecting a plurality of sound conduits 20 with different delay amounts to the same speaker 10 and outputting sound. As a result, frequency resolution and directivity can be maintained even if the number of required speakers 10 is reduced. In addition, this reduces the cost and operating power of the sound output device 100.

[0026] Furthermore, the listening point for the sound from the sound output device 100 may be determined based on the arrangement of the output ends 202 and the difference in sound output timing from the output ends 202. By appropriately controlling the arrangement of the sound conduit 20 and its output ends 202, as well as the output timing, it is possible to easily adjust the position of the sound output range relative to the speaker 10.

[0027] Alternatively, the sound output device 100 may mechanically adjust the listening point by appropriately combining the different path lengths of each sound conduit 20. When the relative positional relationship between the speaker 10 and the listening position is determined to some extent, there is no need to control the timing of sound output, thus reducing the increase in data processing load related to sound output.

[0028] Furthermore, the sound output device 100 may include multiple speakers 10 connected to multiple sound conduits 20 as described above. It is difficult to introduce sound uniformly and at the required volume into many sound conduits 20 from a single speaker 10. Therefore, by inputting the output sound from separate speakers 10 to an appropriate number of sound conduits 20, more accurate sound directivity can be obtained. A decrease in sound resolution and frequency characteristics can be avoided depending on the total number of sound conduits 20.

[0029] Furthermore, the combination of path lengths in the multiple sound conduits 20 may be the same for all of the multiple speakers. Since the timing of the sounds output by the multiple speakers 10 is staggered, the sound conduits 20 only need to determine the delay amount for that timing, thus eliminating the need for sound conduits 20 with extremely long path lengths. In particular, sound conduits 20 with the same path length can be used for all of the multiple speakers 10, limiting the types of path lengths that need to be manufactured. Consequently, the manufacturing cost of the sound conduits 20 is reduced.

[0030] Furthermore, the exit ends 202 of the multiple sound conduits 20 may be arranged in a line in order of their path length. When the direction of sound output is tilted along the direction in which the exit ends 202 are arranged, the direction of sound output can be easily determined while reducing the number of speakers 10 with such an arrangement.

[0031] Alternatively, the multiple sound conduits 20 may be arranged two-dimensionally on the speaker 10. This allows the listening point to be defined two-dimensionally with respect to the speaker 10. Therefore, the sound output device 100 can obtain sound directivity with greater precision.

[0032] Furthermore, the sound conduit 20 has a meandering path between the inlet end 201 and the outlet end 202, and the path length may be determined by the number of meanders. By appropriately patterning the structure of sound conduits 20 with multiple path lengths, the cost required to manufacture multiple types of sound conduits 20 with different path lengths can be reduced.

[0033] It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible. For example, although delay sum beamforming and the tangent method were described above as examples of setting the delay amount, the invention is not limited to these. The delay amount of each sound conduit 20 may be determined by any method that generates sound locally and attenuates it in other regions. Also, if the arrangement of the sound conduits 20 is two-dimensional, the direction of sound output can also be determined two-dimensionally.

[0034] Furthermore, although the sound output direction is limited to one range in the above description, it is not limited to this. Depending on the number of sound conduits 20, the path length of each sound conduit 20 may be determined so that sound is output to two or more ranges.

[0035] Furthermore, the number and arrangement of the sound conduits 20 associated with each speaker 10 do not have to be equal. In this case, the output volume of each speaker 10 may be individually adjusted according to the number of sound conduits 20.

[0036] Furthermore, although the above description assumes that the speaker 10 and the sound conduit 20 are separate components, this is not the only possible configuration. The diaphragm 11 of the speaker 10 and the sound conduit 20 may be an integrated unit. In this case, the diaphragm 11 may be located on the +z side of the path of the sound conduit 20. In this case, the diaphragm 11 may be covered with an appropriate material so that sound is not emitted directly from the +z side of the diaphragm 11, and the sound may be guided to the -z side path.

[0037] Furthermore, the protruding portion 21 is not limited to the shape described above. The protruding portion 21 may have other shapes. Alternatively, the sound conduit 20 may have a groove or hole-like structure corresponding to the path.

[0038] Furthermore, although the timing of sound output from multiple speakers 10 was varied in the above description, this is not the only possible approach. The sound output timing from each speaker 10 may be the same, and the path lengths of the multiple sound conduits 20 corresponding to the multiple speakers 10 may differ. In addition, the specific configuration, processing operation content, and procedures shown in the above embodiment can be modified as appropriate without departing from the spirit of the present invention. The scope of the present invention includes the scope of the invention described in the claims and its equivalents. [Explanation of Symbols]

[0039] 10 Speaker, 20, 20a~20e, 20A~20C Sound conduit, 201 Inlet end, 202 Outlet end, 100 Sound output device

Claims

1. Speakers and, Multiple sound conduits that guide the sound output by the speaker, Equipped with, The aforementioned plurality of sound conduits have different path lengths from the sound inlet end to the sound outlet end. Sound output device.

2. The listening point for the sound is determined based on the arrangement of the output ends and the difference in sound output timing from the output ends according to the path length. The sound output device according to claim 1.

3. The listening point of the sound is determined by the respective different path lengths. The sound output device according to claim 1.

4. Multiple of the aforementioned speakers, Each of the aforementioned multiple speakers is associated with a plurality of sound conduits, The sound output device according to claim 1, comprising:

5. The sound output device according to claim 4, wherein the set of path lengths in the plurality of sound conduits corresponding to each of the plurality of speakers is the same.

6. The sound output device according to claim 1, wherein the output ends of the plurality of sound conduits are arranged in a line in order of the length of the path.

7. The sound output device according to claim 1, wherein the plurality of sound conduits are arranged two-dimensionally on the speaker.

8. The sound output device according to claim 1, wherein the sound conduit has a meandering path between the inlet end and the outlet end, and the path length is determined by the number of meanders.

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