WO2024100821A1 - Dispositif de sortie de signaux acoustiques - Google Patents

Dispositif de sortie de signaux acoustiques Download PDF

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Publication number
WO2024100821A1
WO2024100821A1 PCT/JP2022/041810 JP2022041810W WO2024100821A1 WO 2024100821 A1 WO2024100821 A1 WO 2024100821A1 JP 2022041810 W JP2022041810 W JP 2022041810W WO 2024100821 A1 WO2024100821 A1 WO 2024100821A1
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WO
WIPO (PCT)
Prior art keywords
speaker unit
acoustic signal
output device
signal output
collar
Prior art date
Application number
PCT/JP2022/041810
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English (en)
Japanese (ja)
Inventor
大将 千葉
達也 加古
Original Assignee
日本電信電話株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電信電話株式会社 filed Critical 日本電信電話株式会社
Priority to PCT/JP2022/041810 priority Critical patent/WO2024100821A1/fr
Publication of WO2024100821A1 publication Critical patent/WO2024100821A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/40—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R5/00—Stereophonic arrangements
    • H04R5/02—Spatial or constructional arrangements of loudspeakers

Definitions

  • the present invention relates to an audio signal output technology that can be used in audio systems installed in seats of aircraft, automobiles, etc.
  • earphones or headphones to watch movies or listen to music on airplanes. This is because when using speakers, the playback sound reaches the user's surroundings, causing a nuisance to other users.
  • wearing earphones or headphones can be bothersome for users. Some users do not like wearing them because they mess up their hair. Others dislike the pressure that they put on their ears. Furthermore, wearing earphones or headphones for long periods of time can cause users to feel tired when listening.
  • Patent Document 1 discloses an audio signal output technology for users occupying seats on an aircraft, which can reproduce sounds that cannot be heard by surrounding users without the need for earphones or headphones.
  • Patent Document 1 has the problem that the sweet spot, which is the area in which the emitted sound can be heard, is narrow.
  • the technology of Patent Document 1 also has the problem that two speaker units are always required to emit sound based on one acoustic signal.
  • the present invention aims to provide an audio signal output technology that can enlarge the sweet spot in a limited area near the speaker unit.
  • One aspect of the present invention is a speaker unit pair consisting of two speaker units, a housing that houses a portion of the speaker unit pair so that sound emitted from the two speaker units constituting the speaker unit pair in the rear direction of the speaker unit pair (hereinafter referred to as anti-phase sound) is directed to the front direction of the speaker unit pair, the housing having a hole (hereinafter referred to as a first anti-phase sound emission hole) for emitting the anti-phase sound in the front direction of the speaker unit pair, a baffle that is a member attached to the speaker unit pair so that the anti-phase sound emitted from the first anti-phase sound emission hole and the sound emitted in the front direction of the speaker unit pair from the two speaker units constituting the speaker unit pair (hereinafter referred to as a positive phase sound) do not cancel each other out at a position that is desired to be a sweet spot in the front direction of the speaker unit pair, and a right channel acoustic signal and a left channel acoustic signal are input, and
  • An audio signal output device including an audio signal generating unit that generates a first output audio signal and a second output audio signal using an audio signal for outputting a first output audio signal, outputs the first output audio signal to one speaker unit constituting the speaker unit pair, and outputs the second output audio signal to the other speaker unit constituting the speaker unit pair, and the collar accommodates a part of the speaker unit pair in such a manner that the path from the hole of each speaker unit constituting the speaker unit pair for outputting the anti-phase sound to the first anti-phase sound output hole is short and the resonance frequency of the internal space of the collar formed between the speaker unit pair and the speaker unit pair is high so that the area between the front direction of each speaker unit constituting the speaker unit pair is a sweet spot, and the baffle is attached to the speaker unit pair.
  • the present invention makes it possible to enlarge the sweet spot in a limited area near the speaker unit.
  • FIG. 2 is a diagram for explaining a positive phase sound and a negative phase sound.
  • 1 is a diagram illustrating an example of a configuration of an acoustic signal output device 100.
  • 1 is a diagram illustrating an example of a configuration of an acoustic signal output device 100.
  • 1A and 1B are diagrams illustrating how the acoustic signal output device 100 emits a positive phase sound and a negative phase sound.
  • 1 is a diagram for explaining Helmholtz resonance in the acoustic signal output device 100.
  • FIG. FIG. 1 is a diagram showing an example of an acoustic signal output device 100 including a baffle.
  • 1 is a diagram illustrating an example of a configuration of an acoustic signal output device 100.
  • FIG. 11 is a diagram relating to a first modified example of the first embodiment.
  • FIG. 11 is a diagram relating to a second modified example of the first embodiment.
  • FIG. 11 is a diagram relating to modified example 3 of the first embodiment.
  • FIG. 11 is a diagram relating to a fourth modified example of the first embodiment.
  • FIG. 13 is a diagram relating to a fifth modified example of the first embodiment.
  • FIG. 13 is a diagram relating to a sixth modified example of the first embodiment.
  • FIG. 13 is a diagram relating to modified example 7 of the first embodiment.
  • FIG. 2 is a diagram showing an acoustic signal output device used in an experiment.
  • FIG. 1 is a diagram illustrating an example of a configuration of an acoustic signal output device 100.
  • FIG. 11 is a diagram relating to a first modified example of the first embodiment.
  • FIG. 11 is a diagram relating to a second modified example of the first embodiment.
  • FIG. 11 is a diagram
  • FIG. 13 is a diagram showing experimental results.
  • FIG. 2 is a diagram illustrating an example of the configuration of an acoustic signal output device 200.
  • FIG. 2 is a diagram illustrating an example of the configuration of an acoustic signal output device 200.
  • 1A and 1B are diagrams illustrating how the acoustic signal output device 200 emits a positive phase sound and a negative phase sound.
  • FIG. 2 is a diagram showing an example of an acoustic signal output device 200 including a baffle.
  • FIG. 2 is a diagram illustrating an example of the configuration of an acoustic signal output device 200.
  • FIG. 2 is a diagram illustrating an example of the configuration of an acoustic signal output device 200.
  • FIG. 2 is a diagram illustrating an example of the configuration of an acoustic signal output device 200.
  • FIG. 13 is a diagram relating to a first modified example of the second embodiment.
  • FIG. 13 is a diagram relating to modified example 2 of the second embodiment.
  • FIG. 13 is a diagram relating to modified example 3 of the second embodiment.
  • FIG. 13 is a diagram relating to a fourth modified example of the second embodiment.
  • FIG. 13 is a diagram relating to modified example 5 of the second embodiment.
  • FIG. 13 is a diagram relating to a sixth modified example of the second embodiment.
  • FIG. 13 is a diagram relating to modified example 7 of the second embodiment.
  • FIG. 2 is a diagram showing an acoustic signal output device used in an experiment.
  • FIG. 13 is a diagram showing experimental results.
  • FIG. 3 is a diagram illustrating an example of the configuration of an acoustic signal output device 300.
  • FIG. 3 is a diagram illustrating an example of the configuration of an acoustic signal output device 300.
  • FIG. 3 is a diagram illustrating an example of the configuration of an acoustic signal output device 300.
  • 1A and 1B are diagrams illustrating how the acoustic signal output device 300 emits a positive phase sound and a negative phase sound.
  • 11A and 11B are diagrams for explaining Helmholtz resonance in the acoustic signal output device 300.
  • FIG. 2 is a diagram for explaining the vertical and horizontal directions of a baffle.
  • FIG. 13 is a diagram relating to a first modified example of the third embodiment.
  • FIG. 13 is a diagram relating to a first modified example of the third embodiment.
  • FIG. 13 is a diagram relating to a second modified example of the third embodiment.
  • FIG. 13 is a diagram relating to modified example 3 of the third embodiment.
  • FIG. 4 is a diagram illustrating an example of the configuration of an acoustic signal output device 400.
  • FIG. 5 is a diagram illustrating an example of the configuration of an acoustic signal output device 500.
  • FIG. 5 is a diagram illustrating an example of the configuration of an acoustic signal output device 500.
  • FIG. 1 is a diagram illustrating an example of an in-vehicle acoustic signal output device 500.
  • FIG. 6 is a diagram showing an example of the configuration of an acoustic signal output device 600.
  • FIG. 6 is a diagram showing an example of the configuration of an acoustic signal output device 600.
  • FIG. 6 is a diagram showing an example of an acoustic signal output device 600 having a frame.
  • FIG. 7 is a diagram showing an example of the configuration of an acoustic signal output device 700.
  • FIG. 7 is a diagram showing an example of the configuration of an acoustic signal output device 700.
  • FIG. 7 is a diagram showing an example of an audio signal output device 700 equipped with a ring collar having an illumination function.
  • FIG. 7 is a diagram showing an example of the configuration of an acoustic signal output device 700.
  • an acoustic signal output apparatus is an apparatus that reproduces an input acoustic signal as sound (hereinafter, this sound is referred to as sound based on an acoustic signal), and includes a speaker unit.
  • a speaker unit is an apparatus that converts an acoustic signal into sound.
  • an object to be reproduced is data or a signal from which an acoustic signal can be obtained by a predetermined process, such as data recorded on a CD, DVD, or record, data received via the Internet, or a signal received via a radio or television broadcast.
  • an audio signal output device that reproduces sound based on an audio signal obtained from an object to be reproduced so that only users in the vicinity of the speaker unit can hear it.
  • the sound reproduced by the audio signal output device cannot be heard by users other than the user in the vicinity of the speaker unit.
  • an audio signal output device is used as an audio system for a user using a seat on an airplane, for example, it is possible to provide a system in which only the user using that seat can hear the reproduced sound.
  • such an audio system can also be installed in seats and reclining chairs of vehicles other than airplanes, such as automobiles and trains, and can also be installed in a wearable form, such as worn on the shoulder.
  • positive phase sound sound emitted from a speaker unit in the front direction of the speaker unit
  • negative phase sound sound emitted from a speaker unit in the rear direction of the speaker unit
  • Negative phase sound is sound with a phase opposite to that of positive phase sound, in other words, sound with a phase that is 180 degrees inverted from that of positive phase sound, so positive phase sound and negative phase sound are in an opposite phase relationship.
  • the direction perpendicular to the front and rear directions is called the lateral direction.
  • the acoustic signal output device 100 will be described below with reference to Figures 2 to 8.
  • Figures 2 and 3 are both diagrams showing the configuration of the acoustic signal output device 100, with Figure 2 showing the acoustic signal output device 100 as viewed from the side, and Figure 3 showing the acoustic signal output device 100 as viewed from the front.
  • the acoustic signal output device 100 includes a speaker unit 111 and a collar 112.
  • the speaker unit 111 is a component that includes a diaphragm (not shown) that converts an acoustic signal into vibrations in the air (i.e., generates sound waves).
  • the speaker unit 111 is a component that reproduces an input acoustic signal as sound.
  • the collar 112 is a housing that houses a part of the speaker unit 111. Note that in Figure 2, a part of the speaker unit 111 (the part housed in the collar 112) is shown by a dotted line because it cannot be seen from the side. In addition, in FIG. 2, the part of the speaker unit 111 that emits the positive and negative phase sounds and the collar 112 are shaped like a cone and a bowl, respectively.
  • the plane that forms the front of the speaker unit 111 and the plane that forms the front of the collar 112 are substantially parallel, as shown in FIG. 2. In FIG. 2, the two planes are substantially the same.
  • Collar 112 is a housing for directing the out-of-phase sound, which is the sound emitted from speaker unit 111 toward the rear of speaker unit 111, toward the front of speaker unit 111, and collar 112 is provided with a hole (hereinafter referred to as the first out-of-phase sound emission hole) for emitting the out-of-phase sound that has been directed toward the front of speaker unit 111.
  • the first out-of-phase sound emission hole is indicated by a dashed line because it cannot be seen from the side.
  • the audio signal output device 100 emits a positive phase sound and a negative phase sound. More specifically, the audio signal output device 100 emits a positive phase sound from the speaker unit 111 in the front direction of the speaker unit 111, and emits a negative phase sound from the first negative phase sound emission hole in the front direction of the speaker unit 111. At this time, in order to ensure that only users in the vicinity of the speaker unit 111 can hear the sound and that other users cannot hear the sound, it is preferable that the positive phase sound and the negative phase sound are in an approximately opposite phase relationship on the plane in front of the speaker unit 111.
  • the positive phase sound which is the sound emitted from the speaker unit 111 in the front direction of the speaker unit 111
  • the negative phase sound emitted from the first negative phase sound emission hole in the front direction of the speaker unit 111 are in an approximately opposite phase relationship.
  • the positive phase sound emitted from the speaker unit 111 in the front direction of the speaker unit 111 and the negative phase sound emitted from the first negative phase sound emission hole in the front direction of the speaker unit 111 have a substantially opposite phase relationship.
  • the predetermined frequency band is a band below a frequency (hereinafter referred to as a resonant frequency) at which resonance occurs in the internal space of the collar 112 formed between the speaker unit 111 and the collar 112.
  • the collar 112 accommodates a part of the speaker unit 111 in such a manner that the path from the hole of the speaker unit 111 for emitting the anti-phase sound to the first anti-phase sound emitting hole is short and the resonance frequency of the internal space of the collar 112 formed between the speaker unit 111 and the collar 112 is high so that the anti-phase sound emitted from the first anti-phase sound emitting hole in the front direction of the speaker unit 111 has a substantially anti-phase relationship with the positive phase sound emitted from the speaker unit 111 in the front direction of the speaker unit 111 in a predetermined frequency band in the front direction of the speaker unit 111.
  • the speaker unit 111 is a speaker unit used in a dynamic speaker, the magnet part constituting the speaker unit 111 may be not accommodated in the collar 112.
  • the resonant frequency can be adjusted using one or more of the following three methods, which are to increase the area S of the first anti-phase sound emitting hole, to decrease the volume V of the internal space, or to decrease the length L of the first anti-phase sound emitting hole, taking into consideration the following equation relating to the resonant frequency fH of Helmholtz resonance, so that collar 112 accommodates a portion of speaker unit 111 (see FIG. 5 ).
  • c represents the speed of sound.
  • the lower frequency sound output by the audio signal output device 100 becomes harder to hear the further away from the speaker unit. This is because in the higher frequency range, the phases of the out-of-phase sound and the positive phase sound do not align as they move away from the speaker unit, and so they do not cancel each other out. In contrast, in the lower frequency range, the phases of the out-of-phase sound and the positive phase sound are relatively aligned and cancel each other out even if they move away from the speaker unit.
  • a member (hereinafter referred to as a baffle) is attached to the speaker unit to adjust the position where the out-of-phase sound and the positive phase sound cancel each other out in the lower frequency range to a position far from the speaker unit, thereby adjusting the sweet spot position in front of the speaker unit (see FIG. 6).
  • the speaker unit 111 may be attached with a baffle 113, which is a member for preventing the out-of-phase sound emitted from the first out-of-phase sound emission hole and the positive phase sound emitted from the speaker unit 111 from canceling each other out at the sweet spot position in front of the speaker unit 111.
  • 7 and 8 are both diagrams showing the configuration of the acoustic signal output device 100, with FIG. 7 showing the acoustic signal output device 100 as viewed from the side, and FIG. 8 showing the acoustic signal output device 100 as viewed from the front.
  • the part of the speaker unit 111 that emits the positive and negative phase sounds, the collar 112, and the baffle 113 are shaped like a cone, a bowl, and a plate, respectively.
  • the plane that forms the front of the speaker unit 111, the plane that forms the front of the collar 112, and the plane that forms the front of the baffle 113 are substantially parallel, as shown in FIG. 7.
  • the three planes are substantially the same.
  • the collar 112 may be provided with a hole (hereinafter referred to as a second negative phase sound emitting hole) different from the first negative phase sound emitting hole in order to emit the negative phase sound in a direction other than the front direction of the speaker unit 111 (i.e., a side direction or a rear direction).
  • Fig. 9 is a diagram showing the acoustic signal output device 100 as viewed from the side direction.
  • the second negative phase sound emitting hole may have any shape as long as it is capable of emitting the negative phase sound outside the collar 112.
  • the shape of the second negative phase sound emitting hole may be, for example, a notch shape (see Fig. 9(A)).
  • the second negative phase sound emitting holes may be provided at regular intervals on the side surface of the collar 112 (see Fig. 9(B)).
  • the sound pressure of the anti-phase sound can be released in a direction other than the front direction of the speaker unit 111, and the wave characteristics of the anti-phase sound emitted from the first anti-phase sound emission hole change.
  • the collar 112 may have a cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • Fig. 10 is a diagram showing the acoustic signal output device 100 as viewed from the side.
  • the shapes of the diaphragm of the speaker unit 111 and the collar 112 are both approximately circular and have approximately the same center, and the collar 112 may have a substantially cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a substantially cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • the baffle 113 may have a cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • Fig. 11 is a diagram showing the acoustic signal output device 100 as viewed from the side.
  • the shapes of the diaphragm of the speaker unit 111 and the baffle 113 when viewed from the front of the speaker unit 111 are both approximately circular and have approximately the same center, and the baffle 113 may have a substantially cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a substantially cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • the out-of-phase sound and the in-phase sound merge at a position farther in front of the speaker unit 111, making it possible to position the sweet spot in front of the speaker unit 111 farther away from the speaker unit 111.
  • Fig. 12 is a diagram showing the acoustic signal output device 100 as viewed from the front.
  • the size of the collar 112 increases in the long axis direction when viewed from the front of the speaker unit 111, making it possible to suppress sound leakage toward the rear of the speaker unit 111.
  • the shape of the diaphragm of speaker unit 111 when viewed from the front of speaker unit 111 is approximately circular
  • the shapes of collar 112 and baffle 113 when viewed from the front of speaker unit 111 are approximately elliptical
  • the center of the diaphragm of speaker unit 111 when viewed from the front of speaker unit 111, the center of collar 112, and the center of baffle 113 may be approximately coincident when viewed from the front of speaker unit 111.
  • the major axis direction of collar 112 and the major axis direction of baffle 113 when viewed from the front of speaker unit 111 may be approximately parallel.
  • Fig. 13 is a diagram showing the acoustic signal output device 100 as viewed from the front.
  • a vibration-proofing material that is a member for suppressing vibration of the collar 112 may be attached to the collar 112.
  • Fig. 14 is a diagram showing the acoustic signal output device 100 as viewed from the side.
  • a sound-absorbing material that is a member with sound-absorbing properties may be used as a member for suppressing vibration of the collar 112.
  • vibration-proofing material By installing vibration-proofing material, it is possible to prevent collar vibrations from causing sound leakage.
  • the shape of collar 112 when viewed from the front of speaker unit 111 may be approximately square so that the peaks and valleys of resonance in the high and mid ranges are gentler. That is, the shape of the diaphragm of speaker unit 111 when viewed from the front of speaker unit 111 is approximately circular, the shape of collar 112 when viewed from the front of speaker unit 111 is approximately square, and the center of the diaphragm of speaker unit 111 and the center of collar 112 when viewed from the front of speaker unit 111 are approximately coincident (see FIG. 15(A)).
  • the collar approximately square in shape the distance from the center to a point on the side changes. This suppresses the change in the volume of high and mid-range sounds that accompanies the movement of the user's head, making it possible to suppress difficulty in hearing and discomfort.
  • the center of the diaphragm of the speaker unit 111 and the center of the collar 112 may be offset by a specified distance when viewed from the front of the speaker unit 111 (see FIG. 15(B)). This makes it possible to further reduce hearing difficulties and discomfort.
  • FIG. 15 shows the acoustic signal output device 100 as seen from the front.
  • Figure 17 shows the experimental results.
  • Figures 17(A), 17(B), and 17(C) respectively show sound leakage from audio signal output device 100, an audio signal output device including only a speaker unit, and an audio signal output device including a speaker unit and a sealed speaker box, where the horizontal axis is frequency (in Hz) and the vertical axis is sound pressure level (SPL (Sound Pressure Level), in dB).
  • SPL Sound Pressure Level
  • a collar is used to house part of the speaker unit in order to suppress sound leakage in the side and rear directions, but since the speaker unit is covered from the side, resonance that causes phase inversion of the anti-phase sound may occur. Therefore, in this embodiment, a form in which a member that opens in the side direction is used instead of the collar will be described.
  • Figs. 18 and 19 are both diagrams showing the configuration of the acoustic signal output device 200, with Fig. 18 showing the acoustic signal output device 200 as viewed from the side, and Fig. 19 showing the acoustic signal output device 200 as viewed from the front.
  • the acoustic signal output device 200 includes a speaker unit 111 and a color baffle 212.
  • the color baffle 212 is a member attached to the speaker unit 111.
  • the part of the speaker unit 111 that emits the positive phase sound and the negative phase sound, the color baffle 212 are shaped like a cone and a plate, respectively.
  • the plane in front of the speaker unit 111 and the plane in front of the color baffle 212 are approximately parallel, as shown in FIG. 18.
  • the color baffle 212 is a component for redirecting the out-of-phase sound, which is the sound emitted from the speaker unit 111 toward the rear of the speaker unit 111, toward the front of the speaker unit 111.
  • the color baffle 212 is a component with an open shape on the front and side of the speaker unit 111 so that the out-of-phase sound that has been redirected is emitted in the front and side directions of the speaker unit 111.
  • the audio signal output device 200 emits a positive phase sound and a negative phase sound. More specifically, the audio signal output device 200 emits a positive phase sound from the speaker unit 111 in the front direction of the speaker unit 111, and emits a negative phase sound from the opening between the speaker unit 111 and the color baffle 212 in the front direction and the side direction of the speaker unit 111. At this time, in order to ensure that only users in the vicinity of the speaker unit 111 can hear the sound and that other users cannot hear the sound, it is preferable that the positive phase sound and the negative phase sound have a relationship of approximately opposite phase on the plane in front of the speaker unit 111.
  • the positive phase sound which is the sound emitted from the speaker unit 111 in the front direction of the speaker unit 111
  • the negative phase sound emitted from the opening between the speaker unit 111 and the color baffle 212 in the front direction of the speaker unit 111 have a relationship of approximately opposite phase.
  • a member for adjusting the position where the opposite phase sound and the positive phase sound cancel each other out in the low frequency range may be attached to the speaker unit to adjust the sweet spot in the front direction of the speaker unit (see FIG. 21).
  • the speaker unit 111 may be attached with a baffle 113, which is a member for preventing the opposite phase sound emitted from the opening between the speaker unit 111 and the color baffle 212 and the positive phase sound emitted from the speaker unit 111 from canceling each other out at the sweet spot in the front direction of the speaker unit 111.
  • FIG. 22 and FIG. 23 are diagrams showing the configuration of the acoustic signal output device 200, FIG.
  • FIG. 22 is a diagram showing the acoustic signal output device 200 as viewed from the side
  • FIG. 23 is a diagram showing the acoustic signal output device 200 as viewed from the front.
  • the size of the baffle 113 when viewed from the front of the speaker unit 111 should be smaller than the size of the color baffle 212 when viewed from the front of the speaker unit 111.
  • the size of the baffle 113 when viewed from the front of the speaker unit 111 may be adjustable by the user to change the desired position of the sweet spot in the front direction of the speaker unit 111.
  • the range of adjustment by the user should be within a range that does not exceed the size of the color baffle 212 when viewed from the front of the speaker unit 111.
  • the parts of the speaker unit 111 that emit positive and negative phase sounds, the color baffle 212, and the baffle 113 are shaped like a cone, a plate, and a plate, respectively.
  • the plane that forms the front of the speaker unit 111, the plane that forms the front of the color baffle 212, and the plane that forms the front of the baffle 113 are substantially parallel, as shown in FIG. 22.
  • the plane that forms the front of the speaker unit 111 and the plane that forms the front of the baffle 113 are substantially the same.
  • the color baffle 212 may be provided with holes (hereinafter, referred to as "reverse phase sound emitting holes”) for emitting the reverse phase sound in the rear direction of the speaker unit 111.
  • Fig. 24 is a diagram showing the acoustic signal output device 200 as viewed from the rear direction.
  • the reverse phase sound emitting holes may have any shape as long as they are capable of emitting the reverse phase sound outside the color baffle 212.
  • the shape of the reverse phase sound emitting holes may be, for example, a notch shape (see Fig. 24(A)).
  • the color baffle 212 may be provided with reverse phase sound emitting holes at regular intervals (see Fig. 24(B)).
  • the sound pressure of the anti-phase sound can be released toward the rear of the speaker unit 111, and the wave characteristics of the anti-phase sound emitted from the opening between the speaker unit 111 and the color baffle 212 change.
  • the wave characteristics of the anti-phase sound emitted from the opening between the speaker unit 111 and the color baffle 212 change.
  • the color baffle 212 may have a cylindrical member extending from a plane that is the front of the color baffle 212 in the front direction of the speaker unit 111, or may have a shape that extends in a cylindrical shape from a plane that is the front of the color baffle 212 in the front direction of the speaker unit 111.
  • the length of the cylinder is set to a length that maintains the openness of the side direction of the speaker unit 111.
  • Fig. 25 is a diagram showing the state of the acoustic signal output device 200 as viewed from the side direction.
  • the shape of the diaphragm of the speaker unit 111 and the color baffle 212 are both approximately circular, and their centers are approximately the same, and the color baffle 212 may have a substantially cylindrical member extending from a plane that is the front of the color baffle 212 in the front direction of the speaker unit 111, or may have a shape that extends in a substantially cylindrical shape from a plane that is the front of the color baffle 212 in the front direction of the speaker unit 111.
  • the baffle 113 may have a cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • Fig. 26 is a diagram showing the acoustic signal output device 200 as viewed from the side.
  • the shapes of the diaphragm of the speaker unit 111 and the baffle 113 when viewed from the front of the speaker unit 111 are both approximately circular and have approximately the same center, and the baffle 113 may have a substantially cylindrical member extending from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111, or may have a shape that extends in a substantially cylindrical shape from a plane that is the front of the speaker unit 111 in the front direction of the speaker unit 111.
  • the out-of-phase sound and the in-phase sound merge at a position farther in front of the speaker unit 111, making it possible to position the sweet spot in front of the speaker unit 111 farther away from the speaker unit 111.
  • Fig. 27 is a diagram showing acoustic signal output device 200 as viewed from the front.
  • the size of the color baffle 212 increases in the long axis direction when viewed from the front of the speaker unit 111, making it possible to suppress sound leakage toward the rear of the speaker unit 111.
  • the shape of the diaphragm of speaker unit 111 when viewed from the front of speaker unit 111 is approximately circular
  • the shapes of color baffle 212 and baffle 113 when viewed from the front of speaker unit 111 are approximately elliptical
  • the center of the diaphragm of speaker unit 111 when viewed from the front of speaker unit 111, the center of color baffle 212, and the center of baffle 113 may be approximately coincident.
  • the major axis direction of color baffle 212 and the major axis direction of baffle 113 when viewed from the front of speaker unit 111 may be approximately parallel.
  • Fig. 28 is a diagram showing the acoustic signal output device 200 as viewed from the front.
  • a vibration-proofing material that is a member for suppressing vibration of the color baffle 212 may be attached to the color baffle 212.
  • Fig. 29 is a diagram showing the acoustic signal output device 200 as viewed from the side.
  • a sound-absorbing material that is a member with sound-absorbing properties may be used as a member for suppressing vibration of the color baffle 212.
  • vibration-proofing material By installing vibration-proofing material, it is possible to prevent vibrations from the color baffle from causing sound leakage.
  • the shape of the diaphragm of the speaker unit 111 when viewed from the front of the speaker unit 111 may be substantially circular
  • the shape of the color baffle 212 when viewed from the front of the speaker unit 111 may be substantially square
  • the center of the diaphragm of the speaker unit 111 when viewed from the front of the speaker unit 111 may be substantially the same as the center of the color baffle 212 (see FIG. 30(A)).
  • the center of the diaphragm of the speaker unit 111 when viewed from the front of the speaker unit 111 may be offset by a specified distance from the center of the color baffle 212 (see FIG. 30(B)). This makes it possible to further reduce hearing difficulties and discomfort.
  • FIG. 30 shows the acoustic signal output device 200 as seen from the front.
  • the performance of the acoustic signal output device 200 with a small baffle size (see FIG. 31(A)), the acoustic signal output device 200 with a medium baffle size (see FIG. 31(B)), and the acoustic signal output device 200 with a large baffle size (see FIG. 31(C)) will be compared and verified.
  • the baffle and color baffle of each acoustic signal output device 200 are all square shaped when viewed from the front of the speaker unit.
  • the baffle size and color baffle size both refer to the length of one side of a square, and the baffle sizes of each acoustic signal output device 200 are 9 cm, 13 cm, and 17 cm, and the color baffle sizes are all 17 cm.
  • Figure 32 shows the experimental results.
  • Figures 32(A), 32(B), and 32(C) respectively show sound leakage from an acoustic signal output device 200 with a small baffle size, an acoustic signal output device 200 with a medium baffle size, and an acoustic signal output device 200 with a large baffle size, with the horizontal axis being frequency (in Hz) and the vertical axis being sound pressure level (SPL (Sound Pressure Level), in dB).
  • SPL Sound Pressure Level
  • the sweet spot may be narrow. Therefore, in the present embodiment, a form using a plurality of speaker units will be described.
  • Figs. 33 and 34 are both diagrams showing the configuration of the acoustic signal output device 300, with Fig. 33 showing the acoustic signal output device 300 as viewed from the side, and Fig. 34 showing the acoustic signal output device 300 as viewed from the front.
  • the acoustic signal output device 300 includes a speaker unit pair 311 consisting of two speaker units 111, a collar 312, and a baffle 313.
  • the acoustic characteristics of the two speaker units 111 that constitute the speaker unit pair 311 are approximately the same, and the same acoustic signal is input.
  • the fronts of the two speaker units 111 that constitute the speaker unit pair 311 are, for example, on approximately the same plane.
  • the collar 312 is a housing that houses a part of the speaker unit pair 311. Note that in Fig. 33, a part of the speaker unit 111 (the part housed in the collar 312) is shown by a dotted line because it cannot be seen from the side. In addition, in FIG. 33, the part of the speaker unit 111 that emits the positive and negative phase sounds, the shape of the collar 312, and the shape of the baffle 313 are cone-shaped, elongated bowl-shaped, and plate-shaped, respectively.
  • the plane in front of the speaker unit pair 311, the plane in front of the collar 312, and the plane in front of the baffle 313 are substantially parallel, as shown in FIG. 33.
  • the three planes are substantially the same.
  • the collar 312 is a housing for directing the out-of-phase sound, which is the sound emitted from the two speaker units 111 constituting the speaker unit pair 311 toward the rear of the speaker unit pair 311, toward the front of the speaker unit pair 311, and the collar 312 is provided with a hole (hereinafter referred to as the first out-of-phase sound emission hole) for emitting the out-of-phase sound that has been directed toward the front of the speaker unit pair 311.
  • the first out-of-phase sound emission hole is indicated by a dashed line in FIG. 33 because it cannot be seen from the side.
  • the audio signal output device 300 emits a positive phase sound and a negative phase sound. More specifically, the audio signal output device 300 emits a positive phase sound from the speaker unit 111 in the front direction of the speaker unit pair 311, and emits a negative phase sound from the first negative phase sound emission hole in the front direction of the speaker unit pair 311. At this time, in order to ensure that only users in the vicinity of the speaker unit pair 311 can hear the sound and that other users cannot hear the sound, it is preferable that the positive phase sound and the negative phase sound have an approximately opposite phase relationship on the plane in front of the speaker unit 111.
  • the positive phase sound which is the sound emitted from the speaker unit 111 in the front direction of the speaker unit pair 311, and the negative phase sound emitted from the first negative phase sound emission hole in the front direction of the speaker unit pair 311 have an approximately opposite phase relationship.
  • a predetermined frequency band in the front direction of the speaker unit pair 311 it is preferable that the positive phase sound emitted from the speaker unit 111 in the front direction of the speaker unit pair 311 and the negative phase sound emitted from the first negative phase sound emission hole in the front direction of the speaker unit pair 311 have a substantially opposite phase relationship.
  • the predetermined frequency band is a band below a frequency (hereinafter referred to as a resonant frequency) at which resonance occurs in the internal space of the collar 312 formed between the speaker unit pair 311 and the baffle 313.
  • the collar 312 accommodates a part of the speaker unit 111 in such a manner that the path from the hole of each speaker unit 111 constituting the speaker unit pair 311 for emitting the anti-phase sound to the first anti-phase sound emitting hole is short and the resonance frequency of the internal space of the collar 312 formed between the speaker unit pair 311 and the baffle 313 is high so that the anti-phase sound emitted from the first anti-phase sound emitting hole in the front direction of the speaker unit pair 311 has a substantially anti-phase relationship with the positive phase sound emitted from the speaker unit 111 in the front direction of the speaker unit pair 311 in a predetermined frequency band in the front direction of the speaker unit pair 311.
  • the speaker unit 111 is a speaker unit used in a dynamic speaker, the magnet part constituting the speaker unit 111 may be not accommodated in the collar 312.
  • the resonance frequency can be adjusted using one or more of the following three methods, taking into consideration equation (1) relating to the resonance frequency fH of the Helmholtz resonance: increasing the area S of the first anti-phase sound emitting hole, decreasing the volume V of the internal space, or shortening the length L of the first anti-phase sound emitting hole, so that the collar 312 accommodates a part of the speaker unit pair 311 (see FIG. 36 ).
  • a baffle 313 is attached to the speaker unit pair 311, which is a member for preventing the anti-phase sound emitted from the first anti-phase sound emission hole and the positive-phase sound, which is the sound emitted in the front direction of the speaker unit pair 311 from the two speaker units 111 that constitute the speaker unit pair 311, from canceling each other out at a position that is intended to be the sweet spot in the front direction of the speaker unit pair 311.
  • the baffle 313 is also attached to the speaker unit pair 311 in order to make the area between the front directions of the speaker units 111 that constitute the speaker unit pair 311 the sweet spot.
  • the baffle 313 is attached to the speaker unit pair 311 in a manner that connects the opposing sides of one speaker unit 111 and the other speaker unit 111 that constitute the speaker unit pair 311.
  • the speaker unit 111 has a baffle 313 attached to the side facing the other speaker unit 111, but does not have a baffle 313 attached to the side opposite the side facing the other speaker unit 111, making it possible to reduce sound leakage in the side and rear directions, similar to the acoustic signal output device 100.
  • the collar 312 causes the out-of-phase sound to wrap around to the front of the speaker unit pair 311, making it possible to reduce high-frequency sound leakage in the rear direction of the speaker unit pair 311.
  • the baffle 313 is attached to the speaker unit pair 311 in order to make the area between the front faces of the speaker units 111 that make up the speaker unit pair 311 a sweet spot.
  • the size of the sweet spot between the front faces of the speaker units 111 that make up the speaker unit pair 311 depends on the vertical and horizontal lengths of the baffle 313. In other words, if the vertical length of the baffle 313 is increased, the size of the sweet spot will increase vertically, and if the horizontal length of the baffle 313 is increased, the size of the sweet spot will increase horizontally. Therefore, both the vertical length of the baffle 313 and the horizontal length of the baffle 313 may be determined according to the size of the area between the front faces of the speaker units 111 that make up the speaker unit pair 311 that is desired to be the sweet spot.
  • the speaker units 111 constituting a speaker unit pair 311 may be arranged so that the planes that form the front faces of the respective speaker units 111 are not on the same plane.
  • the two speaker units 111 are arranged so that the angle formed by the front directions of the two speaker units 111 is an acute angle that is less than 45 degrees.
  • the number of speaker units included in the acoustic signal output device 300 may be, for example, four.
  • FIG. 42 is a diagram showing the configuration of the acoustic signal output device 400.
  • the acoustic signal output device 400 includes a speaker unit pair 311 consisting of two speaker units 111, a collar 312, a baffle 313, and an acoustic signal generation unit 420.
  • the acoustic signal output device 400 differs from the acoustic signal output device 300 only in that it further includes an acoustic signal generation unit 420.
  • the acoustic signal generation unit 420 can be configured using, for example, a general-purpose computer.
  • the acoustic signal generation unit 420 is realized by a general-purpose computer by storing a program for realizing the functions of the acoustic signal generation unit 420 in an external storage device or ROM, loading the program and data required for processing the program into RAM as necessary, and processing the program appropriately with the CPU.
  • the acoustic signal generation unit 420 may be configured by a processing circuit.
  • the acoustic signal generating unit 420 is a component that receives an acoustic signal for the right channel and an acoustic signal for the left channel, generates a first output acoustic signal and a second output acoustic signal using the acoustic signal for the right channel and the acoustic signal for the left channel, outputs the first output acoustic signal to one speaker unit 111 constituting the speaker unit pair 311, and outputs the second output acoustic signal to the other speaker unit 111 constituting the speaker unit pair 311.
  • the acoustic signal generating unit 420 may output the input acoustic signal for the right channel and the acoustic signal for the left channel as is without signal processing.
  • the first output acoustic signal is an acoustic signal for the right channel
  • the second output acoustic signal is an acoustic signal for the left channel.
  • the audio signal generating unit 420 may also generate and output a first output audio signal and a second output audio signal from the input right channel audio signal and left channel audio signal as audio signals that increase the size of the sweet spot. To this end, the audio signal generating unit 420 generates the first output audio signal and the second output audio signal by performing signal processing to mix the input right channel audio signal and left channel audio signal to obtain a new audio signal.
  • the audio signal generating unit 420 generates an audio signal obtained by mixing the right channel audio signal and the left channel audio signal in a ratio of r:1-r as the first output audio signal, and generates an audio signal obtained by mixing the right channel audio signal and the left channel audio signal in a ratio of 1-r:r as the second output audio signal.
  • the mixing coefficient r may be a value that depends on the frequency, and a different mixing coefficient may be used for each frequency.
  • the present invention it is possible to enlarge the sweet spot in a limited area near the speaker unit.
  • the phases of the negative phase sound and the positive phase sound are relatively aligned and cancel each other out even if the speaker unit is far away, so the low frequency sound may be perceived as weak. Therefore, in this embodiment, a configuration using a woofer, which is a speaker unit for reproducing low frequencies, and a tweeter, which is a speaker unit for reproducing high frequencies, will be described.
  • Figs. 43 and 44 are both diagrams showing the configuration of the acoustic signal output device 500, with Fig. 43 showing the acoustic signal output device 500 as viewed from the side, and Fig. 44 showing the acoustic signal output device 500 as viewed from the front.
  • the acoustic signal output device 500 includes a first acoustic signal output section 510 and a second acoustic signal output section 520.
  • the first acoustic signal output section 510 includes a woofer 511, which is a speaker unit for reproducing low-frequency sounds, and a first collar 512.
  • the first collar 512 is a housing that houses a part of the woofer 511.
  • the second acoustic signal output section 520 includes a tweeter 521, which is a speaker unit for reproducing high-frequency sounds, and a second collar 522.
  • the second collar 522 is a housing that houses a part of the tweeter 521.
  • a part of the woofer 511 (the part housed in the first collar 512)
  • a part of the tweeter 521 (the part housed in the second collar 522) are shown by dotted lines because they cannot be seen from the side. Also, in Fig.
  • the part of the woofer 511 that emits the in-phase sound and the out-of-phase sound, and the first collar 512 are respectively cone-shaped and bowl-shaped.
  • the part of the tweeter 521 that emits the in-phase sound and the out-of-phase sound, and the second collar 522 are respectively cone-shaped and bowl-shaped.
  • the plane in front of the woofer 511 and the plane in front of the first collar 512 are substantially parallel, as shown in FIG. 43.
  • the plane in front of the tweeter 521 and the plane in front of the second collar 522 are substantially parallel, as shown in FIG. 43.
  • the four planes are substantially the same.
  • the first collar 512 is a housing for allowing the out-of-phase sound (hereinafter referred to as the first out-of-phase sound) emitted from the woofer 511 in the direction of the rear of the woofer 511 to go around in the front direction of the woofer 511, and the first collar 512 is provided with a hole (hereinafter referred to as the first out-of-phase sound emission hole) for emitting the first out-of-phase sound that has gone around in the front direction of the woofer 511.
  • the first out-of-phase sound emission hole for emitting the first out-of-phase sound that has gone around in the front direction of the woofer 511.
  • the second collar 522 is a housing for allowing the out-of-phase sound (hereinafter referred to as the second out-of-phase sound) emitted from the tweeter 521 in the direction of the rear of the tweeter 521 to go around in the front direction of the tweeter 521, and the second collar 522 is provided with a hole (hereinafter referred to as the second out-of-phase sound emission hole) for emitting the second out-of-phase sound that has gone around in the front direction of the tweeter 521.
  • the first out-of-phase sound emission hole and the second out-of-phase sound emission hole are both shown by dashed lines in FIG. 43 because they cannot be seen from the side.
  • the first collar 512 accommodates a part of the woofer 511 in such a manner that the path from the hole of the woofer 511 for emitting the first anti-phase sound to the first anti-phase sound emitting hole is short and the frequency at which the internal space of the first collar 512 formed between the woofer 511 and the first collar 512 resonates (hereinafter referred to as the resonant frequency) is high so that the first anti-phase sound emitted from the first anti-phase sound emitting hole has a substantially anti-phase relationship with the sound emitted from the woofer 511 in the front direction of the woofer 511 in a predetermined frequency band in the front direction of the woofer 511.
  • the resonant frequency the frequency at which the internal space of the first collar 512 formed between the woofer 511 and the first collar 512 resonates
  • the predetermined frequency band is preferably a band lower than the resonant frequency of the internal space of the first collar 512 formed between the woofer 511 and the first collar 512.
  • the magnet part constituting the woofer 511 may be not accommodated in the first collar 512.
  • the resonant frequency can be adjusted using one or more of the following three methods, taking into consideration equation (1) relating to the resonant frequency fH of Helmholtz resonance: increasing the area S of the first anti-phase sound emitting hole, decreasing the volume V of the internal space, or shortening the length L of the first anti-phase sound emitting hole, so that first collar 512 accommodates a portion of woofer 511.
  • the second collar 522 accommodates a part of the tweeter 521 in such a manner that the path from the hole of the tweeter 521 for emitting the second anti-phase sound to the second anti-phase sound emitting hole is short and the frequency at which resonance occurs in the internal space of the second collar 522 formed between the tweeter 521 and the second collar 522 (hereinafter referred to as the resonant frequency) is high so that the second anti-phase sound emitted from the second anti-phase sound emitting hole has a substantially anti-phase relationship with the sound emitted from the tweeter 521 in the front direction of the tweeter 521 in a predetermined frequency band in the front direction of the tweeter 521.
  • the resonant frequency the frequency at which resonance occurs in the internal space of the second collar 522 formed between the tweeter 521 and the second collar 522
  • the predetermined frequency band is desirably a band lower than the resonant frequency of the internal space of the second collar 522 formed between the tweeter 521.
  • the magnet part constituting the tweeter 521 may be prevented from being housed in the second collar 522.
  • the resonance frequency may be adjusted by using one or more of the following three methods, taking into consideration the equation (1) relating to the resonance frequency fH of the Helmholtz resonance: increasing the area S of the second opposite-phase sound emission hole, decreasing the volume V of the internal space, and shortening the length L of the second opposite-phase sound emission hole, so that the second collar 522 may house a part of the tweeter 521.
  • the second acoustic signal output unit 520 is placed near the user's ears to suppress sound leakage.
  • there are two second acoustic signal output units 520 one for emitting a right channel acoustic signal and the other for emitting a left channel acoustic signal.
  • the second acoustic signal output unit 520 for emitting the right channel acoustic signal may be placed near the user's right ear
  • the second acoustic signal output unit 520 for emitting the left channel acoustic signal may be placed near the user's left ear.
  • a member (hereinafter referred to as a baffle) may be attached to the woofer to adjust the position where the out-of-phase sound and the in-phase sound cancel each other out in the low range so that it is far from the woofer, thereby adjusting the desired sweet spot in the front direction of the woofer.
  • the woofer 511 may be attached with a first baffle (not shown), which is a member for preventing the first out-of-phase sound emitted from the first out-of-phase sound emission hole and the first in-phase sound emitted from the woofer 511 from canceling each other out at the desired sweet spot in the front direction of the woofer 511.
  • a baffle may be attached to the tweeter, similar to the woofer.
  • the tweeter 521 may be attached with a second baffle (not shown), which is a member for suppressing sound leakage in the side and rear directions of the tweeter 521.
  • the first acoustic signal output unit 510 equipped with the first baffle can obtain sufficient low-frequency sounds in the vicinity of the woofer 511 by increasing the reproduction voltage. Also, by using a speaker unit with a diameter of about 30 mm as the tweeter 521 and placing the second acoustic signal output unit 520 equipped with the second baffle in a position close to the user's ears, sound leakage can be suppressed.
  • Figure 45 shows an example of an in-vehicle audio signal output device 500 that is installed on the headrest of a car seat.
  • Figure 45(A) shows the device in its exposed state
  • Figure 45(B) shows the device with a cover attached.
  • the in-vehicle audio signal output device 500 has a large woofer located in the center, with small tweeters located to the lower right and lower left of that. With this type of arrangement, the large woofer is located directly behind the user's head, which reduces the cancellation of low-frequency sounds, making it easier for the user to hear low-frequency sounds.
  • a two-way configuration with a woofer and tweeter allows the woofer to enhance low frequencies. Specifically, by driving the woofer, which reproduces low-frequency sounds that tend to be canceled out and difficult to hear, independently of the tweeter, it is possible to apply a larger voltage than the tweeter, making it possible to increase the woofer's output. In addition, by narrowing the frequency band that the tweeter handles to high frequencies and reducing the size of the tweeter, high-frequency sounds that are difficult to suppress from leaking can be reproduced only near the user's ears, making it possible to suppress sound leakage.
  • Figs. 46 and 47 are both diagrams showing the configuration of the acoustic signal output device 600, with Fig. 46 showing the acoustic signal output device 600 as viewed from the side, and Fig. 47 showing the acoustic signal output device 600 as viewed from the front.
  • the acoustic signal output device 600 includes an acoustic signal output section 610 and a direction adjustment section 614.
  • the acoustic signal output section 610 includes a speaker unit 111 and a collar 112.
  • the collar 112 is a housing that houses part of the speaker unit 111.
  • the collar 112 is a housing for directing the out-of-phase sound, which is the sound emitted from the speaker unit 111 toward the rear of the speaker unit 111, toward the front of the speaker unit 111, and the collar 112 is provided with a hole (hereinafter referred to as the first out-of-phase sound emission hole) for emitting the out-of-phase sound that has been directed toward the front of the speaker unit 111.
  • Collar 112 accommodates a part of speaker unit 111 in such a manner that the path from the hole of speaker unit 111 for emitting the anti-phase sound to the first anti-phase sound emitting hole is short and the frequency at which resonance occurs in the internal space of collar 112 formed between collar 112 and speaker unit 111 (hereinafter referred to as the resonant frequency) is high so that the anti-phase sound emitted from the first anti-phase sound emitting hole in the front direction of speaker unit 111 has a substantially anti-phase relationship with the positive phase sound emitted from speaker unit 111 in the front direction of speaker unit 111 in a predetermined frequency band in the front direction of speaker unit 111.
  • the resonant frequency the frequency at which resonance occurs in the internal space of collar 112 formed between collar 112 and speaker unit 111
  • the predetermined frequency band is desirably a band lower than the resonant frequency of the internal space of collar 112 formed between collar 112 and speaker unit 111.
  • the magnet part constituting the speaker unit 111 may be prevented from being housed in the collar 112.
  • the resonance frequency may be adjusted by using one or more of the following three methods, taking into consideration the equation (1) relating to the resonance frequency fH of the Helmholtz resonance: increasing the area S of the first antiphase sound emission hole, decreasing the volume V of the internal space, and shortening the length L of the first antiphase sound emission hole, so that the collar 112 accommodates a part of the speaker unit 111.
  • the direction adjustment unit 614 is a member attached to the audio signal output unit 610 in order to change the front direction of the audio signal output unit 610. By adjusting the direction adjustment unit 614, the user can change the area in which sound leakage is to be suppressed.
  • the direction adjustment unit 614 may be, for example, a member like the arm of a desk lamp (see FIG. 46).
  • the direction adjustment unit 614 may also be a member like a frame attached so as to surround the periphery of the audio signal output unit 610 as shown in FIG. 48(A).
  • the audio signal output device 600 may include two or more audio signal output units 610. In this case, a direction adjustment unit 614 may be attached to each audio signal output unit 610 so that the front direction of the audio signal output unit 610 can be changed (see FIG. 48(B)).
  • the area in which sound cannot be heard is formed on the side of the sound signal output unit 610. Therefore, by using the direction adjustment unit 614 to change the front direction of the sound signal output unit 610 so that a user whom you do not want to hear is positioned on the side of the sound signal output unit 610, it is possible to prevent that user from hearing the sound.
  • a member for adjusting the position where the opposite phase sound and the positive phase sound cancel each other out in the low range may be attached to the speaker unit to adjust the sweet spot in the front direction of the speaker unit.
  • the speaker unit 111 may be attached with a baffle 113, which is a member for preventing the opposite phase sound emitted from the first opposite phase sound emission hole and the positive phase sound emitted from the speaker unit 111 from canceling each other out at the sweet spot in the front direction of the speaker unit 111.
  • the present invention it is possible to enlarge the sweet spot in a limited area near the speaker unit.
  • the user can change the area in which they want to suppress sound leakage.
  • the acoustic signal output device 700 will be described below with reference to Figures 49 to 52.
  • Figures 49 and 50 are both diagrams showing the configuration of the acoustic signal output device 700, with Figure 49 showing the acoustic signal output device 700 as viewed from the side, and Figure 50 showing the acoustic signal output device 700 as viewed from the front.
  • the acoustic signal output device 700 includes a speaker unit 111, a collar 112, and a ring collar 714.
  • the collar 112 is a housing that houses a part of the speaker unit 111.
  • the ring collar 714 is a ring-shaped member having a size that can cover the periphery of the collar 112 in the lateral direction.
  • the shape of the ring collar 714 may be any shape as long as it is large enough to cover the periphery of the collar 112 in the lateral direction.
  • the shape of the ring collar 714 when viewed from the front of the speaker unit 111 may be, for example, approximately circular or approximately elliptical.
  • a baffle (not shown) that is a member for filling the gap may be attached between the collar 112 and the ring collar 714. In this case, it is possible to suppress sound leakage in the direction behind the speaker unit 111.
  • a gap may be provided between the collar 112 and the ring collar 714. In this case, sound can escape in the direction behind the speaker unit 111 from between the collar 112 and the ring collar 714, which results in suppression of sound leakage.
  • the ring collar 714 may have a lighting function.
  • the diaphragm of the speaker unit 111 and the ring collar 714 are both roughly circular in shape and have roughly the same center, and the ring collar 714 may be positioned so as to be located in the lateral direction of the speaker unit 111 (see FIG. 49), or may be positioned so as to be located in the front direction of the speaker unit 111 when viewed from a plane that is the front of the speaker unit 111 (see FIG. 52).
  • the plane that forms the front of the speaker unit 111, the plane that forms the front of the collar 112, and the plane that forms the front of the ring collar 714 are substantially parallel, as shown in FIG. 49.
  • the plane that forms the front of the speaker unit 111 and the plane that forms the front of the collar 112 are substantially the same.
  • the collar 112 is a housing for directing the out-of-phase sound, which is the sound emitted from the speaker unit 111 toward the rear of the speaker unit 111, toward the front of the speaker unit 111, and the collar 112 is provided with a hole (hereinafter referred to as the first out-of-phase sound emission hole) for emitting the out-of-phase sound that has been directed toward the front of the speaker unit 111.
  • Collar 112 accommodates a part of speaker unit 111 in such a manner that the path from the hole of speaker unit 111 for emitting the anti-phase sound to the first anti-phase sound emitting hole is short and the frequency at which resonance occurs in the internal space of collar 112 formed between collar 112 and speaker unit 111 (hereinafter referred to as the resonant frequency) is high so that the anti-phase sound emitted from the first anti-phase sound emitting hole in the front direction of speaker unit 111 has a substantially anti-phase relationship with the positive phase sound emitted from speaker unit 111 in the front direction of speaker unit 111 in a predetermined frequency band in the front direction of speaker unit 111.
  • the resonant frequency the frequency at which resonance occurs in the internal space of collar 112 formed between collar 112 and speaker unit 111
  • the predetermined frequency band is desirably a band lower than the resonant frequency of the internal space of collar 112 formed between collar 112 and speaker unit 111.
  • the magnet part constituting the speaker unit 111 may be prevented from being housed in the collar 112.
  • the resonance frequency may be adjusted by using one or more of the following three methods, taking into consideration the equation (1) relating to the resonance frequency fH of the Helmholtz resonance: increasing the area S of the first antiphase sound emission hole, decreasing the volume V of the internal space, and shortening the length L of the first antiphase sound emission hole, so that the collar 112 accommodates a part of the speaker unit 111.
  • a member for adjusting the position where the opposite phase sound and the positive phase sound cancel each other out in the low range may be attached to the speaker unit to adjust the sweet spot in the front direction of the speaker unit.
  • the speaker unit 111 may be attached with a baffle 113, which is a member for preventing the opposite phase sound emitted from the first opposite phase sound emission hole and the positive phase sound emitted from the speaker unit 111 from canceling each other out at the sweet spot in the front direction of the speaker unit 111.
  • the present invention it is possible to enlarge the sweet spot in a limited area near the speaker unit.
  • a ring collar By using a ring collar, it is possible to suppress sound leakage in the high frequency range. It is also possible to suppress sound leakage in the rear direction.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
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  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)

Abstract

La présente invention comprend : une paire d'unités de haut-parleurs qui est composée de deux unités de haut-parleurs ; un collier, autrement dit un logement conçu pour recevoir une partie de la paire d'unités de haut-parleurs afin de diriger un son à phase inverse émis dans la direction arrière de la paire d'unités de haut-parleurs depuis les deux unités de haut-parleurs constituant la paire d'unités de haut-parleurs autour des unités de haut-parleurs afin qu'il circule dans la direction avant de la paire d'unités de haut-parleurs, et qui est pourvu d'un premier trou d'émission de son à phase inverse conçu pour émettre le son à phase inverse dans la direction avant de la paire d'unités de haut-parleurs ; un déflecteur, autrement dit un élément fixé à la paire d'unités de haut-parleurs afin d'empêcher le son à phase inverse émis par le premier trou d'émission de son à phase inverse et un son à phase positive émis par les deux unités de haut-parleurs constituant la paire d'unités de haut-parleurs dans la direction avant de la paire d'unités de haut-parleurs de s'annuler l'un l'autre en une position qui doit être le point idéal dans la direction avant de la paire d'unités de haut-parleurs ; et une unité de génération de signaux acoustiques qui, sur la base d'un signal acoustique d'un canal droit et d'un signal acoustique d'un canal gauche, génère des premier et second signaux acoustiques de sortie.
PCT/JP2022/041810 2022-11-10 2022-11-10 Dispositif de sortie de signaux acoustiques WO2024100821A1 (fr)

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PCT/JP2022/041810 WO2024100821A1 (fr) 2022-11-10 2022-11-10 Dispositif de sortie de signaux acoustiques

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PCT/JP2022/041810 WO2024100821A1 (fr) 2022-11-10 2022-11-10 Dispositif de sortie de signaux acoustiques

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6195189U (fr) * 1984-11-28 1986-06-19
JPH10224883A (ja) * 1997-01-31 1998-08-21 Nippon Columbia Co Ltd スピーカ装置
JP2008271067A (ja) * 2007-04-19 2008-11-06 Sony Corp ノイズ低減装置および音響再生装置
JP6958763B1 (ja) * 2020-03-26 2021-11-02 日本電信電話株式会社 音響システム
WO2022180686A1 (fr) * 2021-02-24 2022-09-01 日本電信電話株式会社 Système sonore

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6195189U (fr) * 1984-11-28 1986-06-19
JPH10224883A (ja) * 1997-01-31 1998-08-21 Nippon Columbia Co Ltd スピーカ装置
JP2008271067A (ja) * 2007-04-19 2008-11-06 Sony Corp ノイズ低減装置および音響再生装置
JP6958763B1 (ja) * 2020-03-26 2021-11-02 日本電信電話株式会社 音響システム
WO2022180686A1 (fr) * 2021-02-24 2022-09-01 日本電信電話株式会社 Système sonore

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