JP2013081120A - Back mirror for two wheel vehicle and sound reproduction system including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back mirror for a two wheel vehicle which provides high quality sound to a listener who is a driver under a harsh listening environment during driving while maintaining compactness.SOLUTION: A back mirror for a two wheel vehicle (1) provides rear visibility to a driver with a reflector (5) attached to a part of an outer peripheral surface of a housing and reproduces sounds. The reflector (5) is softly supported by the housing in a manner that a rear surface thereof is pressed against a vibration end part of a vibrator (11) fixed to the interior of the housing and drives the vibrator thereby vibrating the reflector to create the plane wave and reproduce the sounds.

Description

  The present invention relates to a rearview mirror for a two-wheeled vehicle that can provide a driver with a rear view by a reflector attached to a part of an outer peripheral surface of a casing and can reproduce sound such as music, and a sound reproduction system including the same.

  It has been studied to attach a speaker to a motorcycle so that a driver can listen to sound such as music even while the motorcycle is running. Here, in a two-wheeled vehicle with a small body frame area, it is difficult to secure a space for attaching a speaker large enough to generate sufficient sound.

  For example, Patent Documents 1 and 2 disclose housing a speaker inside a rearview mirror. Patent Document 1 discloses that an opening of a trumpet (speaker) is provided on the back surface of a rearview mirror. Patent Document 2 discloses that an opening of a speaker is provided on a side of a reflector (mirror).

  Further, Patent Document 3 discloses that a plurality of speakers are distributed and accommodated. More specifically, a high sound speaker (tweeter) is accommodated in the handle cover, a medium sound speaker (squaker) is accommodated in the front body cover, and a low sound speaker (woofer) is accommodated in the rear box. Patent Document 4 discloses that the speaker unit can be detachably mounted on a fuel tank or the like.

  By the way, in a traveling two-wheeled vehicle, the listening environment is an open space, and the surrounding sound becomes noise with respect to the sound reproduced from the speaker, and the listening environment is very severe. In order to enable the driver to practically listen to music or the like given from the speaker in such an open space, it is necessary to match the directivity of the speaker to the driver.

  In the above-mentioned patent document 2, since the rearview mirror is generally directed to the driver, the opening direction of the speaker, that is, the directivity can be adjusted to the driver.

  Further, for example, in Patent Document 5, a pair of thin and highly directional flat speakers may be mounted with the direction of the driver facing between the dash panel of the two-wheeled vehicle and the left and right cowlings, or the handle cover portion. It is disclosed. The flat speaker can be reduced in depth as compared with a conventional cone type or dome type speaker, and can be easily attached even in a small space. In addition, plane waves are generated, sound spread is small, that is, directivity is high, and by attaching the directional axis of the flat speaker toward the driver, the sound information necessary for the driver is hardly leaked to the surroundings. It is stated that it can be communicated reliably.

Utility Model Registration No. 3136890 Utility Model Registration No. 3113610 JP 2002-145154 A JP 2007-084001 A JP 2006-103601 A

  As described above, a flat speaker that generates a plane wave has high directivity and is suitable for use in a severe listening environment during traveling of a two-wheeled vehicle. Therefore, it is expected that a flat speaker is attached to the rearview mirror, and the directivity is matched to the driver, so that sound with good sound quality can be provided. On the other hand, in order to attach the directivity of the flat speaker to the rearview mirror so as to match the driver, it is necessary to enlarge the rearview mirror itself, and as a result, the front view is hindered.

  The present invention has been made in view of the above situation, and the object of the present invention is good for a listener who is a driver even in a severe listening environment while traveling while maintaining compactness. An object of the present invention is to provide a rearview mirror for a motorcycle that can provide a sound with a high sound quality and a sound reproduction system including the same.

  A rearview mirror for a motorcycle according to the present invention is a rearview mirror for a motorcycle that gives a driver a rear view and can reproduce sound by a reflector attached to a part of the outer peripheral surface of the housing, and the reflector is The back surface of the vibrator fixed to the inside of the casing is pressed against the vibration end of the vibrator, and is softly supported by the casing. By driving the vibrator, the reflector is vibrated to generate a plane wave. Sound can be reproduced.

  According to this invention, it is not necessary to attach a new part or the like to the outer peripheral surface of the rear mirror housing, and the reproduced sound can be transmitted to the driver by a plane wave with small attenuation without increasing the size of the housing. A speaker can be incorporated. Therefore, it is possible to provide a sound of good sound quality to the listener who is a driver even in a severe listening environment during traveling while maintaining the compactness of the rearview mirror.

  In the above-described invention, the vibration end portion may be in contact with a position offset from the position of the center of gravity of the reflecting plate. Furthermore, in the above-described invention, the reflecting plate is a substantially flat plate having a substantially rectangular main surface, and the vibration end is in contact with a position offset from an intersection of the substantially rectangular diagonal lines. Good. According to this invention, generation | occurrence | production of the resonance of a reflecting plate can be reduced and the audio | voice of favorable sound quality can be provided to the listener who is a driver | operator.

  The sound reproduction system according to the present invention is a sound reproduction system including a two-wheeled vehicle rearview mirror for providing a driver with a rear view by a reflection plate attached to a part of the outer peripheral surface of the casing. Is flexibly supported by the housing while pressing the back face of the vibration end of the vibrator fixed inside the housing, and the reflection is performed by driving the vibrator by a signal given from an audio driver. It is characterized in that sound can be reproduced by generating a plane wave by vibrating the plate.

  According to this invention, it is not necessary to attach a new part or the like to the outer peripheral surface of the rear mirror housing, and the reproduced sound can be transmitted to the driver by a plane wave with small attenuation without increasing the size of the housing. A speaker can be incorporated. Therefore, it is possible to provide a sound of good sound quality to the listener who is a driver even in a severe listening environment during traveling while maintaining the compactness of the rearview mirror.

  In the above-described invention, the vibration end portion may be in contact with a position offset from the position of the center of gravity of the reflecting plate. Furthermore, in the above-described invention, the reflecting plate is a substantially flat plate having a substantially rectangular main surface, and the vibration end is in contact with a position offset from an intersection of the substantially rectangular diagonal lines. Good. According to this invention, generation | occurrence | production of the resonance of a reflecting plate can be reduced and the audio | voice of favorable sound quality can be provided to the listener who is a driver | operator.

  In the above-described invention, a wind speed sensor may be provided on a part of the outer peripheral surface of the housing, and a signal from the wind speed sensor may be supplied to the audio driver to control the plane wave. According to this invention, the sound to be reproduced can be changed according to the wind speed, and a sound with good sound quality can be provided to a listener who is a driver.

1 is a front view showing a rear-view mirror for a motorcycle according to the present invention. 1 is a cross-sectional view showing a main part of a rear-view mirror for a motorcycle according to the present invention. It is a figure which shows the position of the vibrator | oscillator with respect to a reflecting plate. 1 is a block diagram showing an audio reproduction system including a motorcycle rearview mirror according to the present invention. It is a figure which shows the transverse wave which generate | occur | produces on a flat plate.

  The details of a motorcycle rearview mirror as one embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a motorcycle rearview mirror 1 includes a mirror case 2 provided with an opening at the rear (front side in FIG. 1), a support column 3 for attaching the same to the motorcycle, and a mirror case. 2, a support rubber 4 fixed to the inner peripheral surface of the opening 2, a mirror body 5 for closing the opening of the mirror case 2 to give the driver a rear view, and a back surface of the mirror body 5. And a voice coil 11 housed in the mirror case 2. In the following description, the direction corresponds to the direction of the two-wheeled vehicle to which the two-wheeled vehicle rearview mirror 1 is attached.

  Referring also to FIG. 2, the mirror body 5 is a flat mirror having a substantially rectangular shape when viewed from the front. The mirror body 5 is attached to the mirror case 2 via a support rubber 4 that covers the periphery of the mirror body 5. A rear portion is formed on the outer peripheral surface. In particular, referring to FIG. 2 (b), the support rubber 4 is fixed by sandwiching a support portion 4 a that supports the edge of the mirror body 5 from the front and the back and a protrusion 22 provided at the opening of the mirror case 2. A fixed portion 4c, and a bent portion 4b formed therebetween. By the support rubber 4, the mirror body 5 is softly supported by the mirror case 2 so as to facilitate vibration in the front-rear direction. As will be described later, the mirror body 5 is vibrated by a voice coil 11 that is a vibrator, and generates a plane wave in the air behind to generate sound.

  The front surface of the mirror case 2 is inclined forward from the peripheral edge toward the spherical seat 21. The spherical seat 21 is provided so as to protrude forward slightly from the center of the front surface of the mirror case 2 toward the right, and is in contact with the joint portion 31 of the column 3 to form an angle adjusting mechanism.

  A substantially disc-shaped spacer 12 is fixed to the inner peripheral surface of the mirror case 2 substantially behind the spherical seat 21. A substantially cylindrical voice coil 11 is fixed to the rear surface of the spacer 12 so that its central axis is perpendicular to the main surface of the mirror body 5. That is, the spacer 12 has a role of fixing the voice coil 11 so that the direction of the voice coil 11 is properly maintained with respect to the inner peripheral surface of the inclined mirror case 2.

  The vibration end portion 11 a of the voice coil 11 is brought into contact with the back surface that is the front surface of the mirror body 5 from the inside of the mirror case 2, and the back surface of the mirror body 5 is pressed by the elastic force of the support rubber 4. The vibration end portion 11a may be fixed to the mirror body 5 with an adhesive or the like. The voice coil 11 is connected to a control device to be described later by a lead wire (not shown).

  Further, the support column 3 is provided with a ventilation hole 14 in a part of its outer peripheral surface for conducting the wind from the front to the rear during traveling. A wind speed sensor 13 is installed in the ventilation hole 14. The wind speed sensor 13 is connected to a control device to be described later by a lead wire (not shown), and can give a signal corresponding to the wind speed to the control device. The wind speed sensor 13 is, for example, a vane type sensor, and other known types of sensors can be used.

  Here, as shown in FIG. 3, the position where the voice coil 11 is brought into contact with the mirror body 5 is offset from the intersection P of the diagonal lines L1 and L2 of the main surface which is a substantially rectangular shape of the mirror body 5. . That is, the center of gravity of the mirror body 5 is offset from the front view. Although details will be described later, when the mirror body 5 is vibrated by the voice coil 11, the occurrence of resonance of the mirror body 5 can be reduced.

  Next, an audio reproduction system including the motorcycle rearview mirror 1 will be described with reference to FIG.

  As shown in FIG. 4, the two-wheeled vehicle rearview mirror 1 is configured by connecting a built-in voice coil 11 to a control device 30 to constitute a sound reproduction system. It is preferable to connect the left and right sides of the motorcycle rearview mirror 1 as a pair to the control device 30 so that stereo sound can be reproduced.

  The control device 30 has a built-in digital amplifier and functions as a voice driver that outputs an electrical signal for giving an operation to the voice coil. The digital amplifier includes a low-pass filter and a high-pass filter, and can generate an electrical signal with an output suitable for sound reproduction by the motorcycle rearview mirror 1. Further, an arbitrary audio signal can be input to the control device 30 by connecting a portable digital audio player or the like as a sound source.

  In addition, the control device 30 includes a volume control unit that obtains a signal from the wind speed sensor 13 and calculates the wind speed and can control the output of an electrical signal to the voice coil 11 based on the wind speed. For example, the volume control unit generates a plane wave that automatically adjusts the reproduced sound to an appropriate volume according to the wind speed, such as increasing the volume of the reproduced sound by increasing the output when the wind speed is high. Can be controlled. Thereby, it is not necessary to bother the driver in adjusting the volume. It is also possible to detect the stop and adjust the volume to prevent sound leakage to the surroundings.

  Next, the operation of the sound reproduction system including the motorcycle rearview mirror 1 will be described with reference to FIGS. 2, 4, and 5.

  Referring to FIG. 4, the control device 30 to which an arbitrary audio signal from a sound source (not shown) is input generates an electric signal to be output to the voice coil 11 by amplifying the audio signal. Adjust and output based on wind speed. The voice coil 11 generates vibration in the central axis direction at the vibration end portion 11a based on the electric signal.

  Referring to FIG. 2, the vibration of the vibration end portion 11 a is transmitted to the mirror body 5. The mirror body 5 is given a vibration that translates in the direction of the central axis of the voice coil 11, that is, the front-rear direction, and generates a plane wave that becomes sound in the air behind the mirror body 5. As a result, sound is reproduced and transmitted to a listener who is a driver. A plane wave is advantageous in comparison with a spherical wave because its attenuation is small and deterioration of sound quality can be suppressed in transmission of sound. Further, the mirror body 5 is particularly suitable for transmitting sound by plane waves because the direction of the mirror body 5 is adjusted so as to face the ears slightly outside the driver's eyes in order to give a rear view.

  In the mirror body 5, apart from vibration caused by parallel movement in the front-rear direction that generates a plane wave, a transverse wave that propagates parallel to the main surface is also generated due to its elasticity. When the frequency of the transverse wave becomes a multiple of the natural frequency of the mirror main body 5, the mirror main body 5 may cause resonance. Therefore, it is preferable to reduce the resonance to maintain the sound quality of the reproduced sound.

  For example, as shown in FIG. 5A, it is assumed that the vibrator 111 is in contact with the center of gravity G of the flat plate 105 and gives a transverse wave w1. The transverse wave w1 propagates to the left and right at the same time and is reflected in the same phase at the free end. Eventually, as shown in FIG. 5B, the reflected transverse wave w1 is synthesized at the center of gravity G to become a transverse wave w1 'having a large amplitude. Here, if the vibrator 111 vibrates at a multiple of the natural frequency of the flat plate 105, the transverse wave w2 that is delayed by an integral multiple of the period overlaps with the transverse wave w1 'to generate a larger amplitude. That is, it resonates.

  On the other hand, as shown in FIG. 5C, it is assumed that the vibrator 111 is in contact with a position offset from the center of gravity G of the flat plate 105 and gives a transverse wave w1. The transverse wave w1 propagates to the left and right at the same time and is reflected in the same phase at the free end. Eventually, as shown in FIG. 5D, the reflected transverse wave w1 is synthesized on the opposite side of the position of the transducer 111 across the center of gravity G to become a transverse wave w1 'having a large amplitude. Here, even if the vibrator 111 vibrates at a multiple of the natural frequency of the flat plate 105, the transverse wave w2 that is delayed by an integral multiple of the period does not overlap with the synthesized transverse wave w1 '. That is, resonance can be reduced as compared with the above case. As described above, in order to reduce the resonance of the flat plate 105, it may be effective to bring the vibrator 111 into contact with the position offset from the center of gravity G.

  In the actual two-wheeled vehicle rearview mirror 1, the mirror body 5 is given changes in curvature and thickness. Therefore, the position where the voice coil 11 is brought into contact with the mirror body 5 is determined by more detailed vibration analysis so that the resonance of the mirror body 5 can be further reduced.

  As described above, according to the rear-view mirror 1 for a motorcycle according to the present embodiment, the compactness as the rear-view mirror is maintained and the front view is ensured, and even in a severe listening environment during traveling of the two-wheeler, the attenuation is achieved. It is possible to provide a sound of good sound quality to a driver who is a driver by transmitting sound by a small plane wave. Further, the pair of rearview mirrors 1 have the widest left and right intervals among the members of the two-wheeled vehicle, and when reproducing stereo sound, the realism of stereo sound can be reproduced particularly well.

  The exemplary embodiments according to the present invention have been described so far. However, the present invention is not necessarily limited thereto, and those skilled in the art will appreciate that various modifications can be made without departing from the spirit of the present invention or the scope of the appended claims. Alternative embodiments and modifications may be found.

1 Mirror for motorcycle 2 Mirror case 3 Prop 5 Mirror body 11 Voice coil

Claims (7)

A rearview mirror for a motorcycle that provides a driver with a rear view by a reflector attached to a part of the outer peripheral surface of the housing and can reproduce sound.
The reflector is softly supported by the casing while pressing the back surface thereof against the vibration end of the vibrator fixed inside the casing,
A two-wheeled vehicle rearview mirror capable of generating a plane wave and reproducing sound by driving the vibrator to vibrate the reflector.   2. The rearview mirror for a motorcycle according to claim 1, wherein the vibration end portion is in contact with a position offset from a gravity center position of the reflection plate.   3. The two-wheeled vehicle according to claim 2, wherein the reflecting plate is a substantially flat plate having a substantially rectangular main surface, and the vibration end portion is in contact with a position offset from an intersection of diagonal lines of the substantially rectangular shape. rearview mirror. An audio reproduction system including a rear-view mirror for a motorcycle for providing a driver with a rear view by a reflector attached to a part of the outer peripheral surface of the housing,
The reflector is softly supported by the casing while pressing the back surface thereof against the vibration end of the vibrator fixed inside the casing,
An audio reproduction system characterized in that the reflector is vibrated to generate a plane wave and reproduce an audio by driving the vibrator according to a signal given from an audio driver.   The sound reproducing system according to claim 4, wherein the vibration end portion is in contact with a position offset from a position of the center of gravity of the reflecting plate.   6. The audio reproduction according to claim 5, wherein the reflecting plate is a substantially flat plate having a substantially rectangular main surface, and the vibration end is in contact with a position offset from an intersection of diagonal lines of the substantially rectangular shape. system.   The wind wave sensor is provided in a part of the outer peripheral surface of the casing, and a signal from the wind speed sensor is given to the voice driver to control the plane wave. The described audio reproduction system.

Images