JP2007129487A - Audio signal transmitting and receiving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an audio transmitting and receiving device in which microphones and speakers are arranged closer to each other and which can more effectively prevent an echo from being generated. <P>SOLUTION: The audio signal transmitting and receiving device comprises a device body, a sound radiation unit provided to the device body, and a microphone array 24 constituted by arraying a plurality of unidirectional microphones 241. Thus, the microphone array 24 is used and the microphone array 24 comprises the unidirectional microphones 241, so audio is prevented from reaching the microphone array 24 from the sound radiation unit, the microphones and speakers can be arranged closer to each other, and an echo can more effectively be prevented from being generated. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an audio signal transmitting / receiving apparatus that transmits / receives an audio signal to / from the other party's audio signal transmitting / receiving apparatus.

Conventionally, an audio signal transmitting / receiving apparatus in which a speaker and a microphone are arranged in the same casing has been known (see Patent Document 1). In this audio signal transmitting / receiving apparatus, the voice received from the other party is emitted to the outside of the apparatus by the speaker, and the voice of the user collected by the microphone is transmitted to the other party, so that the call and the audio conference between the other party and the user can be performed. Can be done.
JP-A-8-298696

  In the conventional audio signal transmitting / receiving apparatus described above, the speaker and the microphone must be arranged closer to each other as the size is reduced. For this reason, the sound emitted from the speaker is likely to circulate into the microphone. In the conventional audio signal transmission / reception apparatus, echo cancellation is performed by canceling the wraparound sound by applying signal processing for echo cancellation to the sound signal picked up by the microphone. However, the wraparound is removed only by the sound signal processing. In some cases, it was not possible to sufficiently prevent the occurrence of echo.

  In order to solve the above-described problems, an object of the present invention is to provide an audio transmission / reception device that can arrange a microphone and a speaker closer to each other and can more effectively prevent the occurrence of echoes.

  In order to solve the above problems, the present invention employs the following means.

  (1) The present invention is an audio signal transmitting / receiving apparatus including an apparatus main body, a sound emitting unit disposed in the apparatus main body, and a microphone array in which a plurality of unidirectional microphones are arranged. .

  According to the above configuration, it is possible to collect sound by forming a sound collection beam specialized for a specific sound collection region by the microphone array. As a result, by removing the sound emission part from the sound collection area, it is possible to effectively prevent the sound from being emitted from the sound emission part.

  Furthermore, since each microphone constituting the microphone array is a unidirectional microphone, a sound emitting unit is provided in a direction where the sensitivity of the microphone array is low, and the sound from the sound emitting unit is collected by the microphone array. Can be effectively prevented.

  (2) The present invention is the above-described audio signal transmitting / receiving apparatus, wherein the sound emitting unit is provided in a direction in which the sensitivity of the microphone array is low. According to this configuration, since the sound emitting unit is provided in the direction of low sensitivity of the microphone array, it is possible to effectively prevent the sound from the sound emitting unit from being collected by the microphone array.

  (3) The present invention is the above audio signal transmitting / receiving apparatus, wherein the sound emitting unit is a speaker array in which a plurality of speaker units are arranged, and the arrangement direction of the microphones and the arrangement direction of the speaker units are The sound collecting surface of the microphone array and the sound emitting surface of the speaker array are perpendicular to each other, and the sound collecting direction and the sound emitting direction are arranged on the apparatus main body so as to face each other. Features.

  According to the above configuration, the sound collecting surface and the sound emitting surface are arranged at right angles, and the speaker array can be arranged in the direction of the lowest sensitivity of the unidirectional microphone. The microphone array can be disposed at a position where the sound pressure of the sound from the speaker array is low. As a result, it is possible to more effectively prevent acoustic coupling in which sound from the speaker array is input to the microphone array.

  (4) In the present invention, the audio signal transmission / reception device described above, wherein the device main body includes a frame body for mounting the microphone array, and a plurality of small holes are provided around the mounting positions of the microphones of the frame body. Is formed. In order to effectively cancel the wraparound sound from directions other than the directional direction with a single microphone, it is ideal to arrange in a sound field equivalent to that floating in the air.

  In the present invention, the small holes are formed to effectively prevent the influence of the acoustic resistance due to the frame body, and by this approach to the ideal state, it is more effective in each microphone than the pointing direction. It becomes possible to cancel the wraparound sound from the direction. Moreover, since it is a small hole, it becomes possible to cancel the wraparound sound while ensuring the strength of the frame.

  (5) In the present invention, in the audio signal transmitting / receiving apparatus described above, the frame body is a member having a substantially U-shaped cross section in which at least one edge in a short direction of a long flat plate is bent upward at a substantially right angle. A speaker array is attached to the upper surface of the frame body so that the sound emission direction is on the frame body side, and a hole is formed at the position of the speaker unit, and the bent edge of the frame body is The microphone array is embedded in the longitudinal direction so that the sound collection side is directed to the outside, and the end on the microphone array side on the upper surface of the frame body and the edge where the microphone array of the frame body is disposed The small holes are formed.

  According to the above configuration, the sound emission direction of the speaker array and the sound collection direction of the microphone array can be arranged so as to be orthogonal to each other, and the speaker array can be arranged in a direction where the sensitivity of the microphone array is low. It becomes possible.

  In addition, the small holes on the upper surface of the frame body and the small holes on the edge of the frame body more effectively prevent the influence of acoustic resistance by the frame body, and more effectively wrap around from directions other than the directivity direction within each microphone. It becomes possible to cancel the sound.

  (6) In the present invention, in the audio signal transmitting / receiving apparatus, the small hole is formed at a position where the sound from the speaker array is propagated from the lowest sensitivity direction of the microphone array. It is characterized by. According to this configuration, since the sound from the speaker array propagates to the microphone from the least sensitive direction of the microphone array, the effect of the acoustic resistance due to the frame on the unitary microphone can be reduced by the small holes, It is possible to effectively prevent the sound from the speaker array that has arrived through the small holes from being picked up by the microphone.

  According to the present invention, the sound emission part is removed from the sound collection area, and the sound emission part is provided in a direction in which the sensitivity of the unidirectional microphone is low, thereby effectively preventing the sound from being emitted from the sound emission part. be able to. Thereby, it is possible to effectively prevent the howling from occurring due to the sound that has entered the microphone array while arranging the sound emitting unit and the microphone array closer to each other.

(First embodiment)
The audio signal transmitting / receiving apparatus 1 according to the first embodiment of the present invention will be described below in detail with reference to FIGS. The audio signal transmitting / receiving apparatus 1 is connected to a network such as the Internet or a LAN. The audio signal transmission / reception device 1 transmits / receives an audio signal to / from the other party's audio signal transmission / reception device 1 via the network. Have a meeting.

  FIG. 1 is a perspective view showing an appearance of the audio signal transmitting / receiving apparatus 1. In the following description, the front side of the audio signal transmitting / receiving apparatus 1 is described as Y, the rear side as -Y, the right side as X, and the left side as -X. 2A is a plan view of the audio signal transmitting / receiving apparatus 1 shown in FIG. 1, FIG. 2B is a rear view of the audio signal transmitting / receiving apparatus 1 viewed from the −Y side, and FIG. It is the front view which looked at the audio | voice signal transmission / reception apparatus 1 from the Y side. 3A is a right side view of the audio signal transmitting / receiving apparatus 1 as viewed from the X side, and FIG. 3B is a left side view of the audio signal transmitting / receiving apparatus 1 as viewed from the −X side.

  The audio signal transmission / reception device 1 includes a long, substantially rectangular parallelepiped-shaped device body 2 supported at a predetermined height from an installation surface by substantially rectangular legs 3 that are externally fitted on both sides thereof. The apparatus main body 2 has a top panel 20, a bottom grill 21, and side panels 22 (22A, 22B) as a casing, and is a long-sized speaker array 231 (described later with reference to FIG. 4) inside the casing. A speaker device 23 (described later using FIG. 5) and two rows of microphone arrays 24 (described later using FIG. 5) are provided.

  The speaker array 231 is provided in a row in the longitudinal direction on the lower surface of the speaker device 23, and the microphone array 24 is provided in a row on both side surfaces in the longitudinal direction of the speaker device 23. The configurations of the speaker device 23, the speaker array 231, and the microphone array 24 will be described later in detail.

  The top panel 20 and the side panel 22 are resin panels as covers for the internal structure including the speaker array 231 and the microphone array 24. The top panel 20 is a long member having a U-shaped cross section, and the side panel 22 is a flat plate. Shaped member. Further, the lower grill 21 is a punch mesh steel plate having a substantially U-shaped cross section so as not to disturb sound emission and sound collection of the speaker array 231 and the microphone array 24.

  The operation unit 4 is embedded at the X-side end portion of the upper surface of the upper panel 20, and the LED lighting unit 5 is embedded at substantially the center. As shown in FIG. 2A, the operation unit 4 includes an LCD (Liquid Crystal Display) 41 for displaying a setting state or the like on the −X side, and an operation button group 42 for communication such as a numeric keypad on the X side. Prepare in parallel to be located.

  Further, the operation unit 4 includes an operation button group 43 and an operation button group 44 in parallel on the Y side of the LCD 41 and the operation button group 42. The operation button group 43 is arranged on the −X side with respect to the operation button group 44, and is used to instruct volume up, down, and mute. The operation button group 44 is for changing the setting of the audio signal transmitting / receiving apparatus 1. This setting includes, for example, a selection setting for one of a first lighting mode and a second lighting mode described later.

  Note that the LCD 41 and the operation button groups 42 to 44 are all arranged with the Y side down, and can be operated and confirmed from the Y side.

  The LED lighting unit 5 includes a plurality (five in each embodiment) of linear LED lamps 51 on the −Y side and the Y side. The plurality of LED lamps 51 are arranged so as to be positioned on the same parabola extending in the XX direction. The lighting of each LED lamp 51 is independently controlled by a lighting control unit (not shown) attached to the inside of the top panel 20. Specifically, when the first lighting mode is set by the operation button group 44, the LED lamp 51 is controlled so that the directivity direction of the sound beam from the speaker array 231 described later is turned on. The As a result, the user can check the direction of the sound beam.

  When the second lighting mode is set, control is performed so that the directivity direction of the collected sound beam of the microphone array 24 described later is turned on. For the Y-side microphone array 24, the Y-side LED lamp 51 group is lit, and for the -Y-side microphone array 24, the -Y-side LED lamp 51 is lit. Thereby, it is possible to confirm whether or not sound is input, and the user can confirm the directivity direction of the collected sound beam.

  In the present embodiment, the audio signal transmitting / receiving apparatus 1 has a function of controlling the sound collecting beam in a plurality of areas and detecting the position of the speaker based on the sound collecting level in each area. Therefore, in the second lighting mode, The user can check whether the position of the speaker is erroneously detected.

  Further, the light emission mode is controlled so as to change depending on the volume of the input / output sound. As a result, the user can check whether the sound is input and output at a sufficient volume.

  A connector group 6 with an external device is embedded in the side panel 22 (22A) on the X side (see FIG. 3A). The connector group 6 includes a modular jack 61 for connecting to a LAN such as Ethernet (registered trademark), a network such as the Internet, an audio input terminal 62A and an audio output terminal 62B for connecting to an audio device, and a power source. It consists of a power supply terminal 63.

  By inserting a modular cable plug (not shown) into the modular jack 61, the audio signal transmitting / receiving apparatus 1 can be connected to a network. As a result, the audio signal transmitting / receiving apparatus 1 can be connected to the network and can be communicably connected to the other party's audio signal transmitting / receiving apparatus 1. For this reason, it is possible to perform a telephone call or a voice conference with the other party's voice signal transmitting / receiving apparatus 1, thereby allowing the voice signal transmitting / receiving apparatus 1 to be used as an IP telephone or a voice conference apparatus. .

  FIG. 4 is a bottom view of the audio signal transmitting / receiving apparatus 1 with the lower surface grill 21 removed. FIG. 5 is a perspective view of the central portion of the audio signal transmitting / receiving apparatus 1 of FIG. 6 is a cross-sectional view taken along line AA of the audio signal transmitting / receiving apparatus 1 of FIG. FIG. 7 is a front view of the audio signal transmitting / receiving apparatus 1 of FIG.

  Both the speaker array 231 and the microphone array 24 are attached to a frame 25 that also serves as a baffle for the speaker array 231. The frame 25 is a box-shaped member in which four corners of a rectangular metal plate are bent upward. The speaker array 231 is mounted downward on the inside of the bottom surface of the frame 25, and the microphone array 24 has one row (microphone array 24A) embedded in one side surface (Y side surface) of the frame 25 and the other row (microphone array 24B). Is embedded in the other side surface (the side surface on the -Y side).

  Further, on the upper side of the frame 25, a lower end of a long cylindrical frame 232 (side plate of the present invention) is disposed so as to cover the side surface of the speaker array 231, and both side surfaces (short) of the frame 232 are arranged. The side surface in the hand direction is screwed to the side surface of the frame 25 (folded portion in the short direction). Thus, the frame 25 is formed in a box shape, and the frame body 232 is screwed at the bent portion in the short direction of the frame 25, so that the frame body 232 and the frame 25 can be firmly attached.

  A top plate 233 having substantially the same dimensions as the bottom surface of the frame 25 is disposed at the upper end of the frame body 232 so as to cover the back surface of the speaker array 231. A support plate 26, which is a metal plate-like member, is attached to the side surface (longitudinal bent portion) of the frame 25 by screws 27A, and the upper end of the support plate 26 is bent inward. . The bent portion and the end of the top plate 233 in the short direction are attached by screws 27 </ b> B, whereby the frame body 232 is sandwiched between the top plate 233 and the bottom surface of the frame 25.

  As described above, the housing 23 </ b> A of the speaker array 231 is formed by a portion surrounded by the frame 25, the top plate 233, and the cylindrical frame body 232. A substrate (not shown) on which a control unit (not shown) for performing directivity control of the speaker array 231 and the microphone array 24 is attached to the upper surface of the housing 23A (upper surface of the top plate 233). The speaker device 23 includes a control unit, a housing 23A, and a speaker array 231.

  The speaker array 231 includes a plurality of (for example, 16) speaker units SP arranged in a substantially line shape, and a hole having the same size as the inner diameter of the speaker unit SP at the position of each speaker unit SP on the bottom surface of the frame 25. 251 is formed, and the sound emission side portion of the speaker unit SP is overlapped with the hole 251. In this manner, the bottom surface of the frame 25 and the speaker array 231 are attached by the screws 252 in a state where the speaker unit SP is superimposed on the hole 251. Thus, the sound emitting surface is attached so as to look from the bottom surface, and the sound of each speaker unit SP can be output from the bottom surface.

  As described above, by arranging the speaker array 231 toward the bottom surface of the audio signal transmitting / receiving apparatus 1, the audio beam from the speaker array 231 is output below the audio signal transmitting / receiving apparatus 1. Since the audio signal transmitting / receiving apparatus 1 is supported by the legs 3 at a predetermined height from the installation surface (for example, a table top), the audio beam is reflected by the installation surface and propagates obliquely upward. As a result, it is possible to efficiently provide a sound beam toward the user whose head is located on the YY side of the sound signal transmitting / receiving apparatus 1.

  Moreover, since the leg part 3 has an internal structure, it is possible to provide the user with sound without disturbing the sound emitted by the speaker array 231 or the reflected sound on the installation surface.

  The control unit (not shown) gives a delay time to the audio signal from the other party's audio signal transmission / reception device 1 input via the modular jack 61 (see FIG. 1), thereby controlling the directivity of the audio beam and receiving it from the other party. The D / A conversion or the level of the converted audio signal is amplified on the audio signal and input to the speaker array 231.

  As described above, the microphone array 24 includes a plurality of (for example, 16) microphones 241 arranged in a line over both side surfaces (longitudinal bent portions) of the frame 25. The microphones 241 are non-uniformly arranged so as to be dense toward the inside, and thereby, high-frequency sound with high directivity can be suitably collected.

  The microphone array 24 is supported from the opposite side of the frame 25 by a support plate 26 in which a notch 261 is formed at the position of the microphone 241, and the frame 25 and the support plate 26 in a state where the microphone 241 is fitted in the notch 261. And are screwed. The frame 25 and the support plate 26 constitute a frame body of the present invention.

  As described above, the speaker array 231 is disposed toward the bottom surface of the speaker device 23, and the microphone arrays 24A and 24B are attached toward the side surfaces of the speaker device 23 (toward the side surfaces of the audio signal transmitting / receiving device 1). Thus, the sound collection surface of the microphone array 24 and the sound emission surface of the speaker array 231 can be disposed at a right angle. At the same time, the microphone array 24 and the speaker array 231 can be arranged so that the sound emission direction and the sound collection direction are directed outward.

  By arranging the microphone array 24 and the speaker array 231 in such a positional relationship, the microphone array 24 collects sound in a specific sound collection area with the sound collection beam, and thus the sound from the speaker array 231 is not routed. Dust is hard to occur. Further, the microphone array 24 can be disposed at the position where the sound pressure of the sound from the speaker array 231 is the lowest, and this also effectively prevents the sound from the speaker array 231 from entering the microphone array 24. Is possible.

  Each microphone 241 has a hole (not shown) formed in a side surface position behind the diaphragm (not shown), and the sound from the rear is input through the hole, so that the microphone 241 wraps around the microphone array 24 from the rear. A unidirectional microphone that cancels audio. As described above, by collecting sound by the microphone array 24 including the unidirectional microphones 241, it becomes possible to effectively prevent the sneaking from the speaker array 231, and effectively prevent the generation of echoes. It becomes possible to prevent.

  Further, the speaker array 231 can be arranged in a direction in which the sensitivity (gain) of the microphone 241 is low by arranging the sound collection surface of the microphone array 24 and the sound emission surface of the speaker array 231 at right angles. As a result, it is possible to effectively suppress acoustic coupling in which sound from the speaker array 231 circulates into the microphone array 24. This arrangement also means that the microphone array 24 is arranged in a direction in which the speaker array 231 has low directivity. As a result, it is possible to effectively suppress acoustic coupling in which sound from the speaker array 231 circulates into the microphone array 24.

  Each microphone 241 is attached to the frame 25 such that a hole (not shown) is positioned inside the frame 25, and each microphone 241 on the bottom surface of the frame 25 is used to input sound from the speaker array 231 into this hole. A hole 253 is formed at the rear position. In addition, five round holes 262 </ b> B are formed around each microphone 241 in the support plate 26, and long holes 262 </ b> A are formed between the microphones 241. The holes 253, 262 A, and 262 B are small holes that can secure the strength of the frame 25 and the support plate 26.

  By forming the holes 253, 262A, and 262B as described above, it is possible to prevent the microphone 241 from effectively canceling sound from directions other than the directional direction due to the acoustic resistance of the frame 25 and the support plate 26. It becomes possible. Further, holes 253, 262A, and 262B are formed at positions where the sound from the speaker array 24 reaches the microphone 241 in the direction of the lowest sensitivity of the microphone 241. For this reason, it is effective to pick up the sound from the speaker array 24 with the microphone 241 while the holes 253, 262A, 262B can effectively prevent the influence of the acoustic resistance of the frame 25 and the indicator plate 26. Can be prevented.

  The microphone array 24 is connected to a control unit (not shown) by a signal line (not shown), and thereby inputs each signal collected by each microphone 241 to the control unit. Each input signal is subjected to directivity control by delay control after A / D conversion, and is transmitted to the other party's audio signal transmitting / receiving apparatus 1 via a modular jack 61 (see FIG. 1), a modular cable (not shown), and the like. Sent.

  As described above, in the present embodiment, the microphone array 24 collects sound with the sound collection beam, so that it is possible to effectively prevent the sneak in of the sound from the speaker array 231. Furthermore, each microphone 241 is a unidirectional microphone, and the speaker array 231 is provided in a direction in which the sensitivity of the microphone array 24 is low, so that the sneak in from the speaker array 231 can be more effectively prevented. Accordingly, the sound signal transmitting / receiving apparatus 1 can be made compact by bringing the speaker array 231 and the microphone array 24 close to each other, and the occurrence of echoes can be effectively prevented.

  In the present embodiment, a plurality of microphone arrays 24 are provided. However, the present invention is not limited to this configuration, and any one of the microphone arrays 24A and 24B may be provided.

  The unidirectional microphone is not limited to a configuration in which a hole (not shown) is formed on the side surface behind the diaphragm (not shown), and may have a configuration in which a hole is formed on the back surface.

It is a perspective view which shows the external appearance of an audio | voice signal transmission / reception apparatus. 1A is a plan view of the audio signal transmitting / receiving apparatus shown in FIG. 1, FIG. 2B is a rear view of the audio signal transmitting / receiving apparatus viewed from the −Y side, and FIG. It is the front view seen from. (A) is the right view which looked at the audio | voice signal transmission / reception apparatus 1 from the X side, (B) is the left view which looked at the audio | voice signal transmission / reception apparatus 1 from the -X side. It is a bottom view of the state which removed the grill of the audio signal transceiver. It is a perspective view of the center part of the audio | voice signal transmission / reception apparatus 1 of FIG. It is AA sectional drawing of the audio | voice signal transmission / reception apparatus of FIG. It is a side view of the audio | voice signal transmission / reception apparatus of FIG.

Explanation of symbols

1,1'-Audio signal transmission / reception device 2-Device body 3-Leg 4-Operation unit 231-Speaker array SP-Speaker unit 24 (24A, 24B) -Microphone array 241-Microphone 61-Modular jack (connector) 62B- Audio output terminal (connector) 62A-Audio input terminal (connector)

Claims (6)

The device body;
A sound emitting portion disposed in the apparatus body;
A microphone array in which a plurality of unidirectional microphones are arranged;
An audio signal transmitting / receiving apparatus. The sound emitting part is provided in a direction in which the sensitivity of the microphone array is low,
The audio signal transmitting / receiving apparatus according to claim 1. The sound emitting unit is a speaker array in which a plurality of speaker units are arranged,
The microphone arrangement direction and the speaker unit arrangement direction are parallel, the sound collection surface of the microphone array and the sound emission surface of the speaker array are perpendicular, and the sound collection direction and the sound emission direction are directed outward. Arranged in the apparatus main body,
The audio signal transmitting / receiving apparatus according to claim 1 or 2. The apparatus main body includes a frame for attaching the microphone array, and a plurality of small holes are formed around an attachment position of each microphone of the frame.
The audio signal transmitting / receiving apparatus according to any one of claims 1 to 3. The frame body is a member having a substantially U-shaped cross section in which at least one edge in a short direction of a long flat plate is bent upward at a substantially right angle,
A speaker array is attached to the upper surface of the frame so that the sound emission direction is on the frame, and a hole is formed at the position of the speaker unit.
A microphone array is embedded in the bent edge of the frame body in the longitudinal direction so that the sound collecting side faces outward.
The small hole is formed in the edge on the microphone array side on the upper surface of the frame and the edge where the microphone array of the frame is disposed.
The audio signal transmitting / receiving apparatus according to claim 4. The small hole is formed at a position where the sound from the speaker array propagates from the direction with the lowest sensitivity of the microphone array,
The audio signal transmitting / receiving apparatus according to claim 4.

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