Vehicle existence informing device and method for informing existence of a vehicle

• US 8,600,071 B2
• Filed: 07/19/2010
• Issued: 12/03/2013
• Est. Priority Date: 07/30/2009
• Status: Active Grant

• Current Assignee: DENSO Electronics Corporation (DENSO Corporation)
• Original Assignee: DENSO Corporation
• Inventors: Nakayama, Toshiaki, Hayashi, Toshio
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Tran, Con P
• Application Number:
  US12/838,682
• Publication Number:
  US 20110026729A1
• Time in Patent Office: 1,233 Days
• Field of Search: 381/86, 381/150, 381/59, 381/58, 381/77, 381/82, 381/89, 381/97, 340/425.5, 340/436, 180/271
• US Class Current: 381/86
• CPC Class Codes: B60Q 5/008 for signaling silent vehicles, e.g. for warning that a hybrid or electric vehicle is approaching
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2217/03 Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407

Abstract

A vehicle existence informing device is configured to inform existence of a vehicle by using a warning sound at a frequency in an audible range. A speaker array includes at least two speakers arranged so that oscillation directions of oscillators of the at least two speakers substantially coincide with each other. The speaker array is configured to radiate a warning sound in air on a carrier wave, which is at a frequency in an ultrasonic range. A phase control unit is configured to advance and delay a phase of a sound wave radiated from one of the at least two speakers with respect to a phase of a sound wave radiated from another of the at least two speakers.

Claims

1. A vehicle existence informing device configured to inform existence of a vehicle by using a warning sound at a frequency in an audible range, the vehicle existence informing device comprising:

a speaker array including at least two speakers arranged so that their respective acoustic outputs mix with each other, the speaker array being configured to radiate a warning sound in air on a carrier wave, which is at a frequency in an ultrasonic range; and

a phase control unit configured to advance and delay a phase of an acoustic wave radiated from one of the at least two speakers with respect to a phase of an acoustic wave radiated from another of the at least two speakers;

wherein each of the at least two speakers is configured to produce acoustic oscillations according to application of an electrical voltage or current so as to radiate in air said warning sound on a carrier wave, and

the phase control unit is configured to switch a positive terminal and a negative terminal of one of the at least two speakers so as to advance and delay the phase of an acoustic wave radiated from the one of the at least two speakers with respect to the phase of an acoustic wave radiated from another of the at least two speakers, and

wherein;

the phase control unit is further configured to incline a direction of an acoustic wave by an angle θ

relative to a front direction of the at least two speakers, by switching the positive terminal and the negative terminal, thereby to delay the phase of an acoustic wave radiated from the one of the at least two speakers with respect to the phase of an acoustic wave radiated from another of the at least two speakers by 180 degrees, wherein the angle θ

, a distance d between the oscillators and a wavelength λ

of a sound wave satisfy an equation of d·

sin θ

=λ

/2.

2. The vehicle existence informing device according to claim 1, wherein the phase control unit is configured to switch the positive terminal and the negative terminal by using a relay or switch device.

3. A method for informing existence of a vehicle by using a warning sound at a frequency in an audible range, the vehicle existence informing method comprising:

causing a speaker array to radiate a warning sound in air on a carrier wave, which is at a frequency in an ultrasonic range, the speaker array including at least two speakers arranged so that their respective acoustic outputs mix with each other, each of the at least two speakers is configured to produce acoustic oscillations according to application of an electrical voltage or current so as to radiate in air said warning sound on a carrier wave;

advancing and delaying the phase of a sound wave radiated from one of the at least two speakers with respect to the phase of a sound wave radiated from another of the at least two speakers; and

switching a positive terminal and a negative terminal of one of the at least two speakers so as to advance and delay the phase of an acoustic wave radiated from the one of the at least two speakers with respect to the phase of an acoustic wave radiated from another of the at least two speakers,

wherein the switching further includes;

inclining a direction of an acoustic wave by an angle θ

relative to a front direction of the at least two speakers, by switching the positive terminal and the negative terminal, thereby to delay the phase of an acoustic wave radiated from the one of the at least two speakers with respect to the phase of an acoustic wave radiated from another of the at least two speakers by 180 degrees, wherein the angle θ

, a distance d between the oscillators and a wavelength λ

of a sound wave satisfy an equation of d·

sin θ

=λ

/2.

4. A vehicle existence informing device configured to inform existence of a vehicle by using a warning sound at a frequency in an audible range, the vehicle existence informing device comprising:

a speaker array including at least two speakers arranged so that their respective acoustic outputs mix with each other, the speaker array being configured to radiate a warning sound in air on a carrier wave, which is at a frequency in an ultrasonic range; and

a phase control unit configured to advance and delay a phase of an acoustic wave radiated from one of the at least two speakers with respect to a phase of an acoustic wave radiated from another of the at least two speakers,

wherein each of the at least two speakers is configured to produce acoustic oscillations according to application of an electrical voltage or current so as to radiate a warning sound in air on a carrier wave; and

the phase control unit is configured to switch a positive terminal and a negative terminal of one of the at least two speakers so as to advance and delay a phase of an acoustic wave radiated from the one of the at least two speakers with respect to a phase of an acoustic wave radiated from another of the at least two speakers and thereby to cause three warning sounds including;

a warning sound directed towards a front direction of the speaker array;

a warning sound directed towards a direction inclined by an angle θ

clockwise relative to the front direction; and

a warning sound directed towards a direction inclined by the angle θ

counterclockwise relative to the front direction; and

wherein the angle θ

, a distance d between the oscillators and a wavelength λ

of a sound wave satisfy an equation of d·

sin θ

=λ

/2.

5. A method for informing existence of a vehicle by using a warning sound at a frequency in an audible range, the vehicle existence informing method comprising:

causing a speaker array to radiate a warning sound in air on a carrier wave, which is at a frequency in an ultrasonic range, the speaker array including at least two speakers arranged so that their respective acoustic outputs mix with each other, each of the at least two speakers is configured to produce acoustic oscillations according to application of an electrical voltage or current so as to radiate in air a warning sound on a carrier wave;

advancing and delaying a phase of a sound wave radiated from one of the at least two speakers with respect to a phase of a sound wave radiated from another of the at least two speakers; and

switching a positive terminal and a negative terminal of one of the at least two speakers so as to advance and delay the phase of an acoustic wave radiated from the one of the at least two speakers with respect to the phase of an acoustic wave radiated from another of the at least two speakers,

wherein the switching further includes switching the positive terminal and the negative terminal so as to advance and delay the phase, thereby to cause three warning sounds including;

a warning sound directed towards a front direction of the speaker array;

a warning sound directed towards a direction inclined by an angle θ

clockwise relative to the front direction; and

a warning sound directed towards a direction inclined by the angle θ

counterclockwise relative to the front direction,

wherein the angle θ

, a distance d between the oscillators and a wavelength λ

of a sound wave satisfy an equation of d·

sin θ

=λ

/2.