JP2010206561A - Flat speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an influence of a sound leak on the back side of a flat speaker installed on a ceiling or wall. <P>SOLUTION: The flat speaker includes a dish-like frame 2 having an opening, a flat plate type diaphragm provided in the opening of the frame 2, a driving unit provided in the frame 2 and coupled to the diaphragm to vibrate the diaphragm, and a noise reduction device 3 provided on the opposite side from the diaphragm in a sound output direction, the noise reduction device 3 being configured to output a cancel sound for a sound to be silencing. Thus, the noise reduction device 3 outputs the cancel sound to deaden or reduce a sound which may be offensive to residents of upper-story and adjacent rooms. Consequently, the influence of the sound leak on the back side of the flat speaker 1 can be reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flat speaker used by being installed on a wall or ceiling of a living space such as a house or office building.

  In recent years, in a living space such as a house or office building, a ceiling or wall panel is used as a diaphragm of the speaker, so that a person in the living space can listen to music without feeling the presence of the speaker. Body speaker technology has been proposed.

  However, since this type of speaker is installed on the ceiling or wall, there is a problem that sound leaked to the back side of the speaker can be heard in the upper floor or an adjacent room.

  To solve this problem, the technique described in Patent Document 1 has attempted to solve the problem by installing a soundproof cover that covers the back of the frame as shown in FIG.

  That is, as shown in FIG. 4, the ceiling-mounted speaker 100 of Patent Document 1 is installed by being vertically inserted through the ceiling panel 101, and a grill 102 is attached to the surface of the ceiling panel 101. Most of the ceiling-mounted speaker 100 including the drive unit is installed on the back side of the ceiling panel 101, and the soundproof cover 103 is designed to cover the frame 104.

As described above, the conventional ceiling-mounted speaker 100 is provided with the conical soundproof cover 103 formed of a material such as a hard resin so as to cover the frame 104. As a result, the sound is transmitted from the back side of the ceiling-mounted speaker 100. To prevent leaks.
JP 2007-96546 A

  Certainly, according to the technique described in Patent Document 1, it was possible to prevent sound from leaking to the back side of the ceiling-mounted speaker 100 to some extent.

  However, if there is a gap, for example, at a location that is not covered by the soundproof cover 103 of the ceiling panel 101, the sound once output from the ceiling-mounted speaker 100 into the living space passes through this gap. It is conceivable to wrap around the back side.

  Since the soundproof cover 103 is not effective against sound leakage in such a case, the sound output from the ceiling-mounted speaker 100 may be heard on the upper floor or in an adjacent room.

  In particular, when music mainly composed of low sounds is reproduced by the ceiling-mounted speaker 100, since the low sounds are easily diffracted, there is a high possibility that the sound will sneak to the back side of the ceiling panel 101. It can be a nuisance to the room.

  Therefore, the present invention aims to solve such problems and reduce the influence of sound leakage on the back side of the speaker.

  In order to achieve this object, the flat speaker of the present invention is provided in a dish-shaped frame having an opening, a flat diaphragm provided in the opening of the frame, and the frame. A drive unit coupled to the diaphragm and configured to vibrate the diaphragm; and a noise reduction device provided on a side opposite to an audio output direction of the diaphragm, wherein the noise reduction device is a sound to be silenced. In contrast, an offset sound is output.

  With the above configuration, the present invention can reduce the influence of sound leakage on the back side of the flat speaker.

  This is because the flat speaker of the present invention has a noise reduction device on the side opposite to the sound output direction of the diaphragm.

  In other words, even if the sound wraps around to the back side of the ceiling panel, which is a diaphragm, for some reason, the noise reduction device for the flat speaker according to the present invention outputs a canceling sound to this sound and cancels or reduces it. As a result, the influence of sound leakage on the back side of the flat speaker can be reduced.

(Embodiment 1)
Hereinafter, the structure of the flat speaker 1 of Embodiment 1 is demonstrated using drawing.

  FIG. 1 is a rear view of a flat speaker 1 according to the present embodiment intended to be installed on a ceiling or a wall, and FIG. 2 is a front view of the flat speaker 1. 3 is a cross-sectional view taken along the broken line AA in FIG.

  As shown in the rear view of FIG. 1, an iron frame 2 is attached to the rear surface of the flat speaker 1 in the present embodiment. The frame 2 is a member that supports each constituent member of the flat speaker 1 described in detail later. In the present embodiment, the frame 2 has a substantially square shape in a top view as shown in FIG. A projection 2a is provided at the approximate center of the frame 2, and each member such as the drive unit 10 shown in FIG. 3 is housed inside the projection 2a.

  As the material of the frame 2, in addition to iron, light metal such as aluminum, resin, wood, or the like can be used. In that case, the effect that the weight of the whole speaker becomes light is acquired.

  On the frame 2, a noise reduction device 3 which is a point of the present invention is installed. This noise reduction device 3 is electrically connected to a speaker box 6 having a microphone 4 and a muffler speaker 5 as noise detecting means, a control box 7 as a control unit, and the microphone 4 and the mute speaker 5 and the control box 7. And a cord 8 to be used.

  The microphone 4 is provided on the back side of the flat speaker 1 and collects sound on the back side of the flat speaker 1. That is, a sound that is output from the flat speaker 1 to the living space side, wraps around the back side of the flat speaker 1 through a gap in the ceiling, etc., and collects as a sound to be muffled as a sound to be muffled. To do. The noise information collected by the microphone 4 is input as a signal to the control box 7 via the code 8.

  The control box 7 as a control unit includes a signal processing unit (not shown) and an amplifier (not shown) inside. Based on the signal sent from the microphone 4, the signal processing unit in the control box 7 generates an audio signal (hereinafter referred to as an antiphase signal) having an antiphase with respect to the sound to be silenced. Then, the antiphase signal generated by the signal processing unit is amplified by an amplifier and output to the mute speaker 5 via the cord 8.

  In addition, it processes using the characteristic filter with respect to the antiphase signal produced | generated in the signal processing part, or the wall of the room adjacent to the flat speaker 1 or the space between the flat speaker 1 and an upper floor. It is good also as a structure which performs the signal correction | amendment according to the transmission characteristic which the space between has. In this case, the influence of noise can be further reduced.

  Further, the signal processing unit may be configured to extract a specific frequency component using a bandpass filter and generate an antiphase signal for the extracted frequency component. In particular, in general, humans often find sounds with frequencies of 150 Hz or more and 250 Hz or less to be harsh, and when the configuration is such that sounds in these frequency bands are extracted using a band filter, noise is efficiently generated. Can reduce the effects of

  The muffler speaker 5 is driven based on the reverse phase signal input from the control box 7, and cancels out noise to be muffled in the space between the upper floor and the space between adjacent rooms. Is output. In order to reduce the thickness of the flat speaker 1, for example, it is desirable to use a low-profile speaker with a flat diaphragm, but the shape and configuration are not particularly limited. . As long as it is possible to drive based on the antiphase signal, the effect of reducing the influence of noise can be exhibited.

  Next, a front view of the flat speaker 1 is shown in FIG.

  The diaphragm 9 made of a thin tree that also serves as a ceiling plate and a wall plate is substantially flat, and in the case of the present embodiment, the shape thereof is a quadrangle having a side of 60 cm. Thus, when the flat speaker 1 of the present embodiment is viewed from the front, that is, from the inside of the user's living space, the shape of the flat speaker 1 can be seen only as a ceiling plate or a wall plate, and the user can use the speaker as a speaker. You can enjoy music without feeling the presence of

  Note that another material may be used as the diaphragm 9. For example, the diaphragm 9 can be formed of a light, hard material resin plate, foamed resin plate, metal plate, or the like. In that case, different sound quality can be enjoyed for each material of the diaphragm.

  In the first embodiment, the shape of the diaphragm 9 is a quadrangle, but may be another shape such as a circle or a polygon. In that case, there is an effect that the degree of freedom in designing the speaker is increased.

  Next, a sectional view of the flat speaker 1 is shown in FIG. 3, and each member constituting the flat speaker 1 will be described.

  First, the frame 2 described above has a dish-like shape as can be seen from FIGS. The above-described diaphragm 9 is attached to the opening of the frame 2, and the opening of the frame 2 has a quadrangular shape in accordance with the shape of the diaphragm 9. The opening of the frame 2 is not limited to a square shape. For example, when the shape of the diaphragm 9 is another shape such as a circle or a polygon other than the square shape, the shape of the opening of the frame 2 is also different. You may change according to the shape. The space surrounded by the frame 2 and the diaphragm 9 is in a sealed state.

  The control box 7 and the speaker box 6 are provided on the frame 2 as can be seen from FIG. That is, the control box 7 and the speaker box 6 are provided on the side opposite to the sound output direction of the diaphragm 9. The speaker box 6 has a rectangular cross section as shown in FIG. 3, but the present invention is not limited to this. The muffler speaker 5 is composed of the members (edge 5a, diaphragm 5b, voice coil body 5c, magnetic circuit body 5d) shown in FIG. 3, but this is the same as a general speaker. This is not described in detail.

  The drive unit 10 is installed in a space surrounded by the frame 2 and the diaphragm 9 and is coupled to each of the frame 2 and the diaphragm 9. The drive unit 10 includes a magnetic circuit 11 placed at the center between the inner bottom surface of the frame 2 and the diaphragm 9 and a voice coil bobbin 13 around which a voice coil 12 is wound.

  The magnetic circuit 11 includes a yoke 11a fixed to the center of the bottom of the frame 2, a magnet 11b and an upper plate 11c provided thereon. A magnetic gap 14 is formed between the yoke 11a and the upper plate 11c.

  The voice coil 12 is arranged in the magnetic gap 14 of the magnetic circuit 11, and the voice coil bobbin 13 around which the voice coil 12 is wound is connected via a coupler 15 as a vibration transmission unit that transmits vibration to the diaphragm 9. The diaphragm 9 is connected.

  The damper 16 has a corrugated donut shape, the inner peripheral side thereof is connected to the voice coil bobbin 13, and the outer peripheral side is connected to the peripheral edge of the protrusion 2 a on the inner bottom surface of the frame 2 to support the voice coil bobbin 13. is doing.

  Hereinafter, the operation of the flat speaker 1 in the present embodiment will be described. In the following description, the flat speaker 1 is described as being installed on the ceiling, but the installation location of the flat speaker 1 is not limited to the ceiling.

  When an alternating current to which an audio signal is added is applied from the outside, the drive unit 10 is driven accordingly, and the diaphragm 9 connected to the voice coil bobbin 13 starts vertical vibration. As a result, the air outside the diaphragm 9 vibrates, and sound is output toward the living space.

  Here, for example, when there is a gap or the like between the diaphragm 9 as a ceiling plate and another ceiling plate, the sound output toward the living space goes around the ceiling through this gap.

  The sound that goes around the ceiling in this way becomes a noise for residents on the upper floor.

  Therefore, the flat speaker 1 in the present embodiment is intended to mute such a sound, and tries to reduce the influence of the sound that has entered the back of the ceiling.

  The sound that has entered the back of the ceiling is collected by the microphone 4, converted into an electrical signal, and then output as noise information to the control box 7 via the code 8.

  A signal including noise information input to the control box 7 first reaches a signal processing unit in the control box 7, and this signal processing unit generates an antiphase signal based on the noise information. Here, the signal processing unit generates an antiphase signal with an adaptive filter configured with a digital filter.

  The generated antiphase signal is output from the signal processing unit to the amplifier and amplified. Further, the amplified antiphase signal is input to the muffler speaker 5 and is output from the muffler speaker to the space behind the ceiling as a canceling sound.

  As a result, the sound that has entered the back of the ceiling to be muffled and the canceling sound having anti-phase characteristics with respect to this sound cancel each other, and the sound that has entered the back of the ceiling disappears or is greatly reduced.

  It is desirable that the antiphase signal has the same amplitude as the sound to be silenced. This is because the closer the amplitude of the reverse phase signal is to the amplitude of the sound to be silenced, the more effective the canceling sound of the reverse phase signal.

  Hereinafter, the effect of the flat speaker 1 in this Embodiment is demonstrated.

  First, in the flat speaker 1 of the present embodiment, the influence of sound leakage on the back side of the flat speaker 1 can be reduced.

  That is, as described above, even if the sound output from the flat speaker 1 toward the living space leaks to the back side of the flat speaker 1 through a gap or the like, the noise reduction device 3 causes the flat speaker 1 to Since the sound that wraps around the back of the room is canceled out, it is possible to reduce the possibility of noise for the upper floor and adjacent rooms.

  As described above, in the flat speaker 1 according to the present embodiment, it is possible to reduce the influence of sound leakage to the back side, so that the residents in the living space where the flat speaker 1 is installed are the residents of the upper floor and adjacent rooms. Music and the like can be enjoyed without worrying about inconvenience.

  The noise reduction device 3 is preferably provided on the back surface of the frame 2.

  If the noise reduction device 3 is provided directly on the diaphragm 9 instead of the back surface of the frame 2, there is a possibility that the diaphragm 9 is difficult to vibrate up and down due to weight. In this case, it is difficult for the diaphragm 9 to vibrate up and down in accordance with an audio signal input from the outside, and it becomes difficult to output sound to the living space.

  And the noise reduction apparatus 3 in this Embodiment is implement | achieved by the microphone 4 as a noise detection means, the mute speaker 5, and the control box 7 as a control part.

  If the anti-phase signal generated by the control box 7 is used, it is possible to effectively eliminate or reduce the sound that has entered the back of the ceiling. Therefore, the user of the flat speaker 1 can relax the restriction on the sound output to the living space as compared with the conventional speaker, and can enjoy more diverse music.

  The microphone 4 is preferably provided on the side opposite to the sound output direction of the diaphragm 9.

  When the microphone 4 is provided on the sound output direction side of the diaphragm 9, the sound that is originally output from the diaphragm 9 toward the living space should be picked up and the sound is to be reduced. It is. This can be prevented by setting the microphone 4 on the opposite side of the sound output direction of the diaphragm 9, and this configuration eliminates or reduces only sounds that may be annoying to residents on the upper floor and adjacent rooms. can do.

  Similarly to the installation position of the microphone 4 described above, the sound output direction of the mute speaker 5 is desirably opposite to the sound output direction of the diaphragm 9.

  This is because this configuration does not affect the sound that should be heard by the user, and can eliminate or reduce only the sound that may be a nuisance to residents in the upper floor and adjacent rooms.

  Further, in the flat speaker 1 according to the present embodiment, the drive unit 10 is coupled to the center portion of the frame 2 and the diaphragm 9, but is not limited thereto, and is coupled to be shifted from the center portion. May be. In that case, it is possible to disperse the divided resonance generated on the diaphragm 9, and to obtain a frequency characteristic in which peaks and dip are suppressed.

  The driving unit 10 may be configured using any one of an electrodynamic exciter, a magnetostrictive exciter, and an electrostrictive exciter.

  The flat speaker according to the present invention can eliminate or effectively reduce the influence of the sound that wraps around the back side of the flat speaker by the noise reduction device. Therefore, the user can enjoy music and the like without worrying about inconvenience to residents in the upper floors and adjacent rooms, and the flat speaker according to the present invention can be used for ceiling boards of rooms such as houses, apartments, and offices. It is useful as an acoustic device that also serves as a wall plate.

Rear view of flat speaker according to Embodiment 1 Front view of flat panel speaker according to Embodiment 1 Sectional view (in FIG. 2, broken line AA) of the flat speaker according to Embodiment 1 Cross-sectional view of a conventional ceiling-mounted speaker

DESCRIPTION OF SYMBOLS 1 Flat speaker 2 Frame 2a Protrusion 3 Noise reduction apparatus 4 Microphone 5 Silent speaker 5a Edge 5b Diaphragm 5c Voice coil body 5d Magnetic circuit body 6 Speaker box 7 Control box 8 Code 9 Diaphragm 10 Drive part 11 Magnetic circuit 11a Yoke 11b Magnet 11c Upper plate 12 Voice coil 13 Voice coil bobbin 14 Magnetic gap 15 Coupler 16 Damper

Claims (5)

A dish-shaped frame having an opening;
A flat diaphragm provided in the opening of the frame;
A drive unit provided in the frame and coupled to the diaphragm to vibrate the diaphragm;
A noise reduction device provided on the opposite side of the sound output direction of the diaphragm,
The noise reduction device is a flat speaker that outputs a canceling sound with respect to a sound to be muffled. The flat speaker according to claim 1, wherein the noise reduction device is provided on a back surface of the frame. The noise reduction device is:
Noise detection means for collecting the sound to be silenced,
A control unit to which noise information is input from the noise detection means;
A mute speaker to which a signal is input from the control unit,
2. The flat plate according to claim 1, wherein the control unit generates an antiphase signal for the noise based on the noise information input from the control unit, and outputs the antiphase signal from the mute speaker as the canceling sound. Speaker. The flat speaker according to claim 3, wherein the noise detection means is provided on the opposite side to the sound output direction of the diaphragm. The flat speaker according to claim 3, wherein the sound output direction of the mute speaker is opposite to the sound output direction of the diaphragm.

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