JP2011031695A - Vehicle presence informing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle presence informing device 1 not giving uncomfortable feeling by an informing sound relative to a pedestrian or the like who is not present at a dangerous position and a person who is present in a cabin by only transmitting a pedestrian or the like whom it is required that the danger is informed of the informing sound for notifying the presence of the vehicle 2. <P>SOLUTION: In the vehicle presence informing device 1, an ultrasonic wave is made to a conveying wave, the ultrasonic wave is modulated according to an audible sound, and the informing sound is generated by radiating the modulated ultrasonic wave into air. Although the modulated ultrasonic wave is self-demodulated to become the audible sound during when it advances in air, the self-demodulated audible sound has sufficient directivity like the ultrasonic wave, and the informing sound can be only transmitted to the pedestrian present in a range in which it is required that the danger is informed. Further, an ultrasonic wave speaker 6 is built-in in a door mirror 9. Since the door mirror 9 is projected from a side surface of the vehicle to a side, the sound wave can be radiated toward front and rear sides of the vehicle by a simple structure even if it does not adopt a complicated structure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle presence notification device for notifying a person outside a vehicle such as a pedestrian or a car driver of the presence of the vehicle.

  Conventionally, a speaker has been installed outside the vehicle and the presence of the vehicle from the speaker in order to allow people outside the vehicle to recognize that the vehicle is approaching when driving an electric vehicle or driving a motor of a hybrid car. There is a technique for generating a notification sound (such as a pseudo engine sound or a pseudo running sound) that informs the user (see Patent Documents 1 and 2).

  However, since the sound emitted from the speaker diffuses to the surroundings, a warning sound is heard even by a pedestrian who is not in a dangerous position (for example, a pedestrian behind the vehicle traveling forward) or a person in the passenger compartment. It is uncomfortable for people other than the pedestrian in the position.

JP 2006-199110 A Japanese Patent Laid-Open No. 10-201001

  The present invention has been made in order to solve the above-described problems, and its purpose is not to be in a dangerous position by transmitting a notification sound that informs the existence of a vehicle only to a pedestrian or the like that needs to inform the danger. The object is to prevent discomfort caused by the notification sound to pedestrians and people in the passenger compartment.

[Means of Claim 1]
The vehicle presence notification device according to claim 1 is for reporting the presence of the vehicle to the outside of the vehicle, wherein the ultrasonic wave is used as a carrier wave, and the modulation means modulates the ultrasonic wave according to the audible sound. And a speaker that generates a notification sound by radiating ultrasonic waves into the air.

According to this, while the modulated ultrasonic wave travels in the air, it is self-demodulated to become an audible sound, but this self-demodulated audible sound has good directivity like the ultrasonic wave, and it is necessary to inform the danger. The notification sound can be transmitted only to the pedestrians in the range, and no uncomfortable feeling due to the notification sound is given to a pedestrian who is not in the dangerous position or a person in the passenger compartment. In addition, since the directivity is good, sound can be reliably transmitted to a range where danger is to be notified, so that even a small speaker can sufficiently fulfill the function of notifying the presence of the vehicle.
In addition, since ultrasonic waves tend to attenuate, self-demodulated audible sounds are also easily attenuated, so that notification sounds do not reach pedestrians and other vehicles far from the vehicle, and no noise is generated. .

The vehicle presence notification device according to claim 1 is characterized in that a speaker is built in the door mirror.
Since the door mirror protrudes laterally from the side surface of the vehicle, if a speaker is incorporated in the door mirror so as to emit sound waves in the front-rear direction, a notification sound can be generated from the door mirror toward the front-rear direction of the vehicle.
Further, even when a vehicle presence notification device is attached to a vehicle that is already on the market, only the door mirror needs to be modified, and the modification cost can be reduced.

[Means of claim 2]
According to the vehicle presence notification device of the second aspect, the speaker is incorporated in the door mirror so as to be able to emit sound waves toward the front of the vehicle and the rear of the vehicle.

  In this case, the presence of the vehicle can be recognized by the notification sound to pedestrians in front and rear of the vehicle. Further, as described above, since the door mirror protrudes laterally from the side surface of the vehicle, it is possible to easily emit sound waves toward the front of the vehicle and the rear of the vehicle only by providing a speaker at one location. That is, it is not necessary to provide speakers for the vehicle front and for the vehicle rear at different locations (for example, two locations of the fender and the rear bumper), and the structure is not complicated.

[Means of claim 3]
According to the vehicle presence notification device of the fourth aspect, the reflection plate for bending the course of the sound wave emitted from the speaker is provided, and the sound wave is emitted toward the front of the vehicle and the rear of the vehicle by the reflection plate. I did it.

According to this, the degree of freedom of design when arranging the speaker in a limited space in the door mirror is expanded.
In addition, by providing a reflector, sound can be radiated from one speaker in various directions using reflection of sound waves. For example, it can be designed to radiate sound waves emitted from one speaker in both the front and rear directions of the vehicle by reflecting the sound waves with a reflector.

[Means of claim 4]
According to the vehicle presence notification apparatus of the fourth aspect, the speaker is a speaker array configured by arranging a plurality of ultrasonic speakers.
As a result, the directivity can be further improved as compared with the case where the speaker is constituted by a single ultrasonic speaker.

[Means of claim 5]
According to the vehicle presence notifying device of the fifth aspect, the vehicle is provided with the phase control means for changing the phase of the sound wave emitted from the ultrasonic speaker.
According to this, the direction in which the notification sound is desired to be directed can be changed by making the phases of the sound waves emitted from the plurality of arranged ultrasonic speakers different from each other by the phase control means.

  That is, for example, in the direction in which the notification sound is to be directed, the phase of each sound wave is adjusted so that the peaks of the sound waves radiated from two adjacent speakers are matched and the valleys are matched. Control. Thereby, the presence of the vehicle can be notified by emitting a notification sound in various directions.

[Means of claim 6]
According to the vehicle presence notification apparatus of the sixth aspect, the carrier frequency switching means for changing the ultrasonic frequency of the speaker is provided.

  The position where the ultrasonic wave radiated from the speaker is self-demodulated and can be heard as a notification sound depends on the frequency of the carrier wave. Depends on the frequency (note that the lower the carrier frequency, the farther the position for self-demodulation is from the speaker. The lower the carrier frequency, the farther the position where the notification sound generated by self-demodulation can be heard is farther from the speaker).

  For this reason, by changing the frequency of the carrier wave, it is possible to vary the way the notification sound is heard according to the distance from the speaker.

(A) is the figure of the vehicle which attached the vehicle presence notification apparatus, (b) is the figure of the door mirror and vehicle presence notification apparatus seen from the vehicle left side, (c) is the door mirror and vehicle presence seen from the vehicle front. The figure of an alerting | reporting apparatus, (d) is AA sectional drawing of (b) (Example 1). (A)-(e) is a figure which shows the audible sound radiation | emission principle of a vehicle presence alerting | reporting apparatus (Example 1). (A) is a cross-sectional view of a vehicle presence notification device in a door mirror viewed from the left side of the vehicle, (b) is a diagram of the door mirror viewed from the front of the vehicle, (c) is a diagram of the door mirror viewed from the rear of the vehicle, (d) These are the figures of the door mirror and vehicle presence alerting | reporting apparatus which were seen from the vehicle upper direction (Example 2). (A) is a block diagram of a vehicle presence alerting | reporting apparatus, (b) is BB sectional drawing of (a) (Example 2). (A) is a view of a door mirror and a vehicle presence notification device viewed from the left side of the vehicle, (b) is a view of a door mirror and a vehicle presence notification device viewed from the front of the vehicle, (c) is a view of the door mirror viewed from the rear of the vehicle, (D) is DD sectional drawing of (a) (Example 3). (A) is the figure of the vehicle presence alerting device seen from the vehicle front, (b), (c) is EE sectional drawing of (a) (Example 3). (A) is a figure which shows the amplification state of the sound wave at the time of making the phase of the sound wave radiated | emitted from an adjacent ultrasonic speaker the same, (b) is the phase of the sound wave radiated | emitted from an adjacent ultrasonic speaker. (Example 3) which is a figure which shows the amplification state of the sound wave at the time of making different. (A) is a figure which shows the directivity direction of the notification sound at the time of making the phase of the sound wave radiated | emitted from an adjacent ultrasonic speaker the same, (b) is a figure of the sound wave radiated | emitted from an adjacent ultrasonic speaker. (Example 3) which is a figure which shows the directivity direction of the notification sound at the time of making a phase differ.

A vehicle presence notification apparatus according to a first embodiment for carrying out the present invention notifies the presence of a vehicle to the outside of the vehicle, and includes a modulation unit that uses an ultrasonic wave as a carrier wave and modulates the ultrasonic wave according to an audible sound. And a speaker that generates a notification sound by emitting modulated ultrasonic waves into the air.
A speaker is built in the door mirror.

In the vehicle presence notification device according to the second embodiment for carrying out the present invention, the speaker is built in the door mirror so as to be able to emit sound waves toward the front of the vehicle and the rear of the vehicle.
Further, a reflection plate for bending the course of the sound wave emitted from the speaker is provided, and the sound wave is emitted toward the front of the vehicle and the rear of the vehicle by the reflection plate.
The speaker is a speaker array configured by arranging a plurality of ultrasonic speakers.

  The vehicle presence notification apparatus of the form 3 for implementing this invention is provided with the phase control means to change the phase of the sound wave radiated | emitted from an ultrasonic speaker.

  The vehicle presence notification apparatus according to mode 4 for carrying out the present invention includes carrier frequency switching means for changing the ultrasonic frequency of the speaker.

[Configuration of Example 1]
A configuration of the vehicle presence notification device 1 according to the first embodiment will be described with reference to FIGS.
The vehicle presence notification device 1 is, for example, a notification sound that notifies the presence of the vehicle 2 so that a person outside the vehicle 2 can recognize that the vehicle 2 is approaching when the electric vehicle is traveling or the hybrid vehicle is driven by a motor. (Pseudo engine sound, simulated running sound, etc.) are generated.

  The vehicle presence notification device 1 includes an ultrasonic wave as a carrier wave, a modulation unit 3 that modulates the ultrasonic wave according to an audible sound, and a speaker that generates a notification sound by radiating the modulated ultrasonic wave in the air (detailed later). And an ECU 5 for controlling energization of the modulation means 3 and the speaker.

  The speaker of the present embodiment is composed of one ultrasonic speaker 6. The ultrasonic speaker 6 converts an electric signal such as a voltage input to a vibrator (not shown) into mechanical vibration, and generates a sound wave that vibrates at a frequency in the ultrasonic region by the mechanical vibration. To do.

  The ECU 5 generates audible sound wave signal generating means for outputting an audible sound wave signal (see FIG. 2A) of an audible sound to be reproduced, and generates an ultrasonic signal that outputs an ultrasonic wave signal (see FIG. 2B) that is a carrier wave signal. It has a function as a means.

Then, the audible sound wave signal and the ultrasonic signal from the ECU 5 are input to the modulation / amplification circuit 7, and the modulation circuit of the modulation / amplification circuit 7 modulates the ultrasonic signal according to the audible sound wave signal (FIG. 2 (c). )reference). The modulation / amplification circuit 7 has a modulation circuit and an amplification circuit, and the modulation circuit functions as the modulation means 3.
Based on the modulated ultrasonic wave (modulated wave) signal, the transducer of the ultrasonic speaker 6 vibrates, whereby the modulated wave is emitted from the ultrasonic speaker 6 into the air.

  As the modulated wave radiated into the air travels through the air, the waveform is distorted due to the non-linear characteristics of the air (see FIG. 2D), and the audible sound based on the original audible sound wave signal (FIG. 2E) (See below) is self-demodulated and recognized as a notification sound by a pedestrian or the like.

  The ultrasonic speaker 6 is built in the door mirror 9 on the left side of the vehicle (see FIG. 1). That is, it is arranged in the housing 10 of the door mirror 9 so as to be able to emit sound waves toward the front of the vehicle so as not to interfere with the mirror 11, and sound waves from the ultrasonic speaker 6 can pass through the front wall of the housing 10. As shown in FIG. 1 (c), the sound output port 12 is provided. It should be noted that the sound generation opening 12 may be open to the extent that sound waves can pass, and may be a large number of small holes.

[Effect of Example 1]
The vehicle presence notification device 1 of this embodiment includes an ultrasonic wave as a carrier wave, a modulation unit 3 that modulates the ultrasonic wave according to an audible sound, and a speaker that generates a notification sound by radiating the modulated ultrasonic wave in the air. With.

  According to this, as described above, the modulated ultrasonic wave is self-demodulated to become an audible sound while traveling in the air, but this self-demodulated audible sound has a good directivity and is dangerous like the ultrasonic wave. The notification sound can be transmitted only to pedestrians in a range where it is necessary to notify the user.

  For this reason, discomfort due to the notification sound is not given to a pedestrian or the like who is not in a dangerous position or a person in the passenger compartment. Further, since the directivity is good, it is possible to reliably transmit the sound to the range where the danger is to be notified, so that even the small ultrasonic speaker 6 can sufficiently fulfill the function of notifying the presence of the vehicle 2.

  In addition, since ultrasonic waves tend to attenuate, self-demodulated audible sounds are also easily attenuated, and no notification sounds reach pedestrians or other vehicles 2 far from the vehicle. Not.

  Further, since the ultrasonic speaker 6 is built in the door mirror 9, only the door mirror 9 needs to be modified when the vehicle presence notification device 1 is retrofitted to a commercially available vehicle, and the modification cost is low. Tesumu.

[Configuration of Example 2]
The configuration of the vehicle presence notification device 1 according to the second embodiment will be described with reference to FIGS.
The speaker of the present embodiment is a speaker array 13 configured by arranging a plurality of ultrasonic speakers 6.
For example, the speaker array 13 is arranged in a plane so that the sound wave emission surfaces of the seven ultrasonic speakers 6 face the vehicle lower side. The seven ultrasonic speakers 6 are arranged in a substantially circular shape so that one ultrasonic speaker 6 is surrounded by the other six ultrasonic speakers 6 (see FIG. 4B).

  A first reflecting plate 15 and a second reflecting plate 16 for changing the course of sound waves from the speaker array 13 in the vehicle front-rear direction are provided on the front (lower side) of the radiation surface of the speaker array 13.

If the front side of the vehicle is the radiation surface 19 and the rear side of the vehicle is the radiation surface 20 with respect to the center M of the speaker array 13 in the vehicle longitudinal direction, the first reflector 15 is inclined 45 ° counterclockwise with respect to the radiation surface 19. The second reflection plate 16 is inclined 45 ° clockwise with respect to the radiation surface 20 (see FIGS. 4A and 4B).
The first reflecting plate 15 and the second reflecting plate 16 are provided symmetrically about the center M in the vehicle front-rear direction of the speaker array 13 as a symmetry axis. The first reflecting plate 15 and the second reflecting plate 16 are provided below the mirror 11.

  The sound wave radiated vertically downward from the radiation surface 19 is reflected by the first reflector 15 and travels forward of the vehicle, and the sound wave radiated vertically downward from the radiation surface 20 is reflected by the second reflector 16 on the vehicle 2. The vehicle travels backward (see FIG. 4A).

  In addition, the vehicle presence notification device 1 is provided with peripheral walls 21 and 22 that surround the circumference of the path of the sound wave after being reflected by the first reflecting plate 15 and the second reflecting plate 16. The peripheral walls 21 and 22 are respectively composed of upper and lower walls 23 and 24 surrounding the vehicle vertical direction of the sound wave path and left and right walls 26 and 27 surrounding the vehicle left and right direction. The upper and lower walls 23 and 24 are parallel to the vehicle vertical direction. Provided (see FIG. 4A). In addition, the left and right walls 26 and 27 are provided so as to expand leftward and rightward toward the front of the vehicle on the peripheral wall 21, and are provided to expand leftward and rightward toward the rear of the vehicle on the peripheral wall 22 (FIG. 4B). )reference).

  The modulation / amplification circuit 7 is installed above the speaker array 13, and the speaker array 13 and the modulation / amplification circuit 7 are accommodated in one housing 29. The first reflecting plate 15, the second reflecting plate 16, and the peripheral walls 21 and 22 are formed integrally with the housing 29.

  Further, a sound generation port 30 is opened in the vehicle front wall of the housing 10 of the door mirror 9 so that sound waves traveling forward of the vehicle can pass, and travels rearward of the vehicle below the mirror 11 on the vehicle rear wall of the housing 10. The sound generation port 31 is open so that sound waves can pass (see FIGS. 3B and 3C).

[Effects of Example 2]
In the vehicle presence notification device 1 of this embodiment, a speaker is built in the door mirror 9 so as to emit sound waves toward the front and rear of the vehicle.
In this case, the presence of the vehicle 2 can be recognized by the notification sound to pedestrians in front and rear of the vehicle. Further, since the door mirror 9 protrudes laterally from the side surface of the vehicle, it is possible to easily radiate sound waves toward the front and rear of the vehicle only by providing a speaker at one location. That is, it is not necessary to provide speakers for the vehicle front and for the vehicle rear at different locations (for example, two locations of the fender and the rear bumper), and the structure is not complicated.

The speaker is a speaker array 13 configured by arranging a plurality of ultrasonic speakers 6 side by side.
Thereby, the directivity can be further improved as compared with the case where the ultrasonic speaker 6 is used alone to configure the speaker.

In addition, a first reflector 15 and a second reflector 16 are provided to bend the course of sound waves emitted from the speaker array 13, and the first reflector 15 and the second reflector 16 make the front and rear of the vehicle. A sound wave was emitted toward the head.
As a result, the degree of freedom in designing the speaker array 13 in a limited space in the door mirror 9 is increased.

Further, by providing the first reflecting plate 15 and the second reflecting plate 16, a notification sound can be generated from one speaker array 13 in both the front and rear directions of the vehicle using the reflection of sound waves.
For this reason, it is not necessary to provide the speaker array 13 for generating the notification sound behind the vehicle separately from the speaker array 13 for generating the notification sound in front of the vehicle, and the cost can be reduced.

[Configuration of Example 3]
The configuration of the vehicle presence notification device 1 according to the third embodiment will be described with reference to FIGS.
The speaker of the present embodiment is a speaker array 13 configured by arranging a plurality of ultrasonic speakers 6.
The speaker array 13 is arranged in a plane so that the sound wave emitting surfaces of the ten ultrasonic speakers 6 face the front of the vehicle. Specifically, three ultrasonic speakers 6 are arranged in the left-right direction of the vehicle, four ultrasonic speakers 6 are arranged below the three ultrasonic speakers 6, and three ultrasonic speakers 6 are arranged below the ultrasonic speakers 6 (see FIG. 6B). ).

  In addition, the vehicle presence notification device 1 includes a phase control unit that changes the phase of the sound wave emitted from the ultrasonic speaker 6, and the ECU 5 functions as a phase control unit.

  The phase control means changes the directivity of the notification sound by making the phases of sound waves radiated between the ultrasonic speakers 6 adjacent in the vehicle left-right direction different from each other, for example. Here, the principle of changing the direction of notification sound by changing the phase will be described using three ultrasonic speakers 6a to 6c arranged adjacent to each other (see FIGS. 7 and 8).

  When the phase of the radiated sound wave is the same between the ultrasonic speakers 6a to 6c, as shown in FIG. 7A, the direction in which each transducer of the ultrasonic speakers 6a to 6c vibrates, that is, the speaker array. 13, the peaks of the sound waves radiated from each of the ultrasonic speakers 6 a to 6 c are matched, and the valleys of the sound waves radiated from each are matched. As a result, sound waves are amplified in the direction toward the front of the speaker array 13 and the self-demodulated notification sound is heard loudly, so the notification sound is directed toward the front of the speaker array 13.

  When the phase of the radiated sound wave differs by 180 ° between the ultrasonic speakers 6a and 6b and between the ultrasonic speakers 6b and 6c, as shown by the thick broken line in FIG. In the direction toward the front, the peak of the sound wave emitted from the ultrasonic speaker 6a coincides with the valley of the sound wave emitted from the ultrasonic speaker 6b, and the valley of the sound wave emitted from the ultrasonic speaker 6b and the ultrasonic speaker 6c. The peaks of sound waves radiated from the same. As a result, in the direction toward the front surface of the speaker array 13, the sound waves cancel each other without being amplified.

On the other hand, for example, in the direction inclined by θ from the direction toward the front of the speaker array 13, the peaks of the sound waves emitted from each of the ultrasonic speakers 6 a to 6 c coincide with each other, and the sound waves emitted from each of them The valleys match.
Here, θ is as follows when the distance between the transducers of the ultrasonic speakers 6a and 6b (distance between the transducers of the ultrasonic speakers 6b and 6c) is d and the wavelength of the sound wave is λ. The relationship of Formula 1 is satisfied.
[Formula 1] d · sin θ = λ / 2

As a result, the self-demodulated notification sound is heard loudly in the direction inclined by θ from the direction toward the front of the speaker array 13, and the notification sound is directed in the direction inclined by θ from the direction toward the front of the speaker array 13. .
As shown in FIG. 8B, the direction inclined by θ from the direction toward the front of the speaker array 13 is the direction toward the front of the speaker array 13 as the axis of symmetry, and only θ is clockwise from this axis of symmetry. There are two directions, an inclined direction and a direction inclined by θ counterclockwise.

  For this reason, the direction of the notification sound is changed to the direction of the sound wave emitted from the ultrasonic speakers 6a to 6c, so that only one direction toward the front of the speaker array 13 (see FIG. 8A), Switching is made between two directions (see FIG. 8B), a direction inclined by θ clockwise from the direction toward the front of the speaker array 13 and a direction inclined by θ counterclockwise.

  The phase can be switched by switching a positive terminal and a negative terminal for supplying power to the vibrator of the ultrasonic speaker 6b at a specific time by a relay in accordance with a command from the ECU.

  After the positive electrode terminal and the negative electrode terminal are switched in the ultrasonic speaker 6b, the vibration of the vibrator of the ultrasonic speaker 6b is delayed in phase by 180 ° with respect to the vibration of each of the ultrasonic speakers 6a and 6c. The phase of the radiated sound wave differs by 180 ° between the ultrasonic speakers 6a and 6b, and also differs by 180 ° between the ultrasonic speakers 6b and 6c.

In the present embodiment, using the above-described principle, the phase of the radiated sound wave is alternately changed by 180 degrees between the ultrasonic speakers 6 adjacent to each other in the vehicle left-right direction toward the front of the speaker array 13. Sound waves can be directed in a direction inclined by θ from the direction (see FIG. 6C).
Then, a reflector 33 is provided on the left front side of the speaker array 13 for reflecting sound waves traveling in a direction inclined by θ and radiating them toward the rear of the vehicle (see FIG. 6C).

  That is, when the phases of sound waves radiated from the ultrasonic speakers 6 constituting the speaker array 13 are the same, a notification sound is generated only in front of the vehicle (in the direction toward the front of the speaker array 13) (FIG. 6). (See (b)). When the phases of the sound waves radiated from the ultrasonic speakers 6 adjacent to each other in the left-right direction of the vehicle are alternately varied by 180 degrees, the notification sound is emitted toward the two directions inclined by θ from the front of the vehicle and the rear of the vehicle. (See FIG. 6C).

In addition, the vehicle presence notification device 1 is provided with a peripheral wall 35 that surrounds the path of the sound wave emitted from the speaker array 13. The peripheral wall 35 includes upper and lower walls 36 and 37 that surround the vehicle vertical direction of the sound wave path, and a right wall 39 that blocks the vehicle right direction, and the upper and lower walls 36 and 37 are provided in parallel to the vehicle vertical direction. The right wall 39 is provided so as to expand to the right as it goes forward of the vehicle.
It should be noted that the left side of the speaker array 13 is not blocked in order to generate a sound wave reflected by the reflector 33 provided in front of the left side of the speaker array 13 in the vehicle.

  The modulation / amplification circuit 7 is installed above the speaker array 13, and the speaker array 13 and the modulation / amplification circuit 7 are accommodated in one housing 29. The reflection plate 33 and the peripheral wall 35 are formed integrally with the housing 29.

  Further, a sound generation port 40 is opened in the vehicle front wall of the housing 10 of the door mirror 9 so that sound waves traveling in the front of the vehicle can pass therethrough, and travels backward in the vehicle on the left side of the mirror 11 on the vehicle rear wall of the housing 10. The sound generation port 41 is open so that sound waves can pass through.

[Effects of Example 3]
In the vehicle presence notification device 1 of the present embodiment, the phase control means changes the direction in which the notification sound should be directed by making the phases of sound waves emitted from the plurality of arranged ultrasonic speakers 6 different from each other. Can do. Thereby, the presence of the vehicle can be notified by emitting a notification sound in various directions.

  Further, by combining the reflection of sound waves by the reflector 33 and the setting of the directivity direction by the phase control means, a limited space in the door mirror 9 can be used to connect the front and rear of the vehicle from one speaker array 13. Notification sound can be generated in both directions.

[Configuration of Example 4]
The vehicle presence notification device 1 according to the fourth embodiment includes a carrier frequency switching unit that changes the ultrasonic frequency of the ultrasonic speaker 6 in the vehicle presence notification device 1 according to the first embodiment, and the ECU 5 functions as a carrier frequency switching. . That is, when outputting an ultrasonic signal (see FIG. 2B) that is a carrier wave signal, the ultrasonic frequency is changed.

[Effects of Example 4]
The position at which the ultrasonic wave radiated from the ultrasonic speaker 6 is self-demodulated and can be heard as a notification sound depends on the frequency of the carrier wave. , Depending on the frequency of the carrier (note that the lower the frequency of the carrier, the farther the position of self-demodulation is from the ultrasonic speaker 6, and the lower the frequency of the carrier, the position where the notification sound generated by the self-demodulation cannot be heard. It is far from the ultrasonic speaker 6).

  For this reason, by changing the frequency of the carrier wave, it is possible to vary the way the notification sound is heard according to the distance from the ultrasonic speaker 6.

[Modification]
In the vehicle presence notification device 1 according to the first embodiment, the speaker may be a speaker array 13 including a plurality of ultrasonic speakers 6.

  The vehicle presence notification device 1 according to the second embodiment may include a phase control unit that changes the phase of the sound wave emitted from the ultrasonic speaker 6.

  In the second embodiment, sound waves radiated vertically downward from the speaker array 13 are directed in the vehicle front-rear direction using the first reflecting plate 15 and the second reflecting plate 16. The positions of the reflector and the speaker array can be set so as to be able to emit sound waves toward the front and rear of the vehicle.

  In the fourth embodiment, the vehicle presence notification device 1 according to the first embodiment includes the carrier frequency switching unit. However, the vehicle presence notification device 1 according to the second and third embodiments may include the carrier frequency switching unit.

  In the first embodiment, the speaker is incorporated in the door mirror 9 on the left side of the vehicle. However, the speaker may be provided on the door mirror 9 on the left and right sides of the vehicle or on the door mirror 9 on the right side of the vehicle.

  Further, in the first to fourth embodiments, the notification sound is a pseudo engine sound or pseudo driving for causing a person outside the vehicle 2 to recognize that the vehicle 2 is approaching when the electric vehicle is traveling or when the hybrid car is motor-driven. Although described as a sound or the like, the notification sound is not limited to an electric vehicle or the like, and may be a horn sound that notifies the presence of the vehicle 2 to be used.

DESCRIPTION OF SYMBOLS 1 Vehicle presence notification apparatus 2 Vehicle 3 Modulation means 5 ECU (phase control means, carrier wave frequency switching means)
6 Ultrasonic speaker (speaker)
9 Door mirror 13 Speaker array (speaker)
15 First reflector 16 Second reflector

Claims (6)

In the vehicle presence notification device that notifies the outside of the vehicle of the presence of the vehicle,
Modulation means for modulating ultrasonic waves according to audible sound, with ultrasonic waves as carrier waves;
A speaker that generates a notification sound by radiating the modulated ultrasonic waves into the air,
The vehicle presence notification device, wherein the speaker is built in a door mirror. The vehicle presence notification device according to claim 1,
The vehicle presence notification device, wherein the speaker is incorporated in the door mirror so as to be able to emit sound waves toward the front of the vehicle and the rear of the vehicle. The vehicle presence notification device according to claim 1 or 2,
Providing a reflector for bending the course of sound waves emitted from the speaker;
A vehicle presence notification device characterized in that sound waves are emitted toward the front of the vehicle and the rear of the vehicle by the reflector. In the vehicle presence notification device according to any one of claims 1 to 3,
The vehicle presence notification device, wherein the speaker is a speaker array configured by arranging a plurality of ultrasonic speakers. The vehicle presence notification device according to claim 4,
A vehicle presence notification device comprising phase control means for changing a phase of a sound wave radiated from the ultrasonic speaker. In the vehicle presence notification device according to any one of claims 1 to 5,
A vehicle presence notification device comprising carrier frequency switching means for changing an ultrasonic frequency of the speaker.

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