JP2019220924A - Wearable sound output device and drive control method of the same - Google Patents

Abstract

To provide a wearable sound output device for removing an influence of an external sound noise and an abnormal vibration of a speaker diaphragm due to air column resonance with high accuracy without providing an air hole or a sound absorbing material in a housing.SOLUTION: The wearable sound output device includes: a vibration measurement sensor (204) for detecting a measurement value indicating a vibration state of a diaphragm in a speaker; a drive unit (diaphragm drive unit 105) for vibrating the diaphragm; a drive amplifier circuit (201) for supplying a drive signal to the drive unit for giving a vibration corresponding to an input signal to the diaphragm; and a correction control unit (203) for obtaining a vibration state of the diaphragm from the measurement value of the vibration measurement sensor and correcting and controlling the drive signal in accordance with the vibration state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wearable sound output device that controls vibration of a diaphragm of a speaker and a drive control method of the wearable sound output device.

In order to easily listen to music and the like outside the room, headphones such as an ear covering type that wraps around the auricle of the wearer or an ear mounting type that is placed on the auricle, or an earphone that is inserted inside the ear (a canal that is inserted into the ear canal) (Including type).
The above-described headphones and earphones (hereinafter, referred to as wearable sound output devices) include a speaker unit that outputs an acoustic sound and a housing (cabinet) that covers the speaker unit (for example, see Patent Document 1).

The housing of the wearable acoustic output device is provided with a plate-like member (hereinafter, referred to as a sound-absorbing material) having sound absorbing properties and acoustic resistance, an air hole, and the like, thereby suppressing external noise and air column resonance in the ear canal. For this purpose, the acoustic impedance of the speaker to the diaphragm is formed.
The above-described configuration having an acoustic impedance that suppresses the vibration of the diaphragm in the speaker suppresses the vibration of the diaphragm in the speaker of the speaker unit, thereby causing abnormal vibration of the speaker diaphragm due to noise of external sound and air column resonance. And the sound quality of the acoustic sound heard by the user is improved.

JP 2010-2322982 A

However, the suppression of the diaphragm using the acoustic impedance also suppresses vibration caused by driving corresponding to an acoustic signal such as music heard by the user.
For this reason, the response to the driving of the sound signal in the predetermined frequency region on the diaphragm is deteriorated due to the acoustic impedance, and the sound quality of the acoustic sound heard by the user may be reduced.

In recent years, there is a wearable acoustic output device provided with ANC (active noise canceling) for removing the influence of external sound noise on a diaphragm of a speaker with high accuracy.
However, when performing vibration suppression control corresponding to external noise on the diaphragm using the above-described ANC, driving of the diaphragm in ANC control is similar to abnormal vibration due to external sound noise or air column resonance. To be reduced.
For this reason, the vibration suppression control by the ANC becomes incomplete, the effect of removing the influence of the noise of the external sound with high accuracy is reduced, and the influence of the noise of the external sound is likely to be adversely affected by the provision of the sound absorbing material. is there.

  The present invention has been made in view of such a situation, and does not provide an air hole or a sound absorbing material in a housing, and accurately detects abnormal noise of a speaker diaphragm due to noise of external sound or air column resonance. A wearable sound output device to be removed and a drive control method for the wearable sound output device are provided.

  In order to solve the above-described problem, one embodiment of the present invention provides a vibration measurement sensor that detects a measurement value indicating a vibration state of a diaphragm in a speaker, a driving unit that vibrates the diaphragm, and an input signal. A drive signal for providing the vibration to the vibration plate, a drive amplifier circuit for supplying the driving unit, the vibration state of the vibration plate is obtained from the measurement value of the vibration measurement sensor, corresponding to the vibration state And a correction control unit that corrects and controls the drive signal.

  In one aspect of the present invention, the vibration measurement sensor is a current detection unit that detects a current value of a drive current flowing through a coil in the drive unit in response to the drive signal as the measurement value, A control unit, wherein a correction signal corresponding to the measured value is positively fed back to an input of the drive amplifier circuit, and the control unit controls the drive signal equivalently using an output impedance of the drive amplifier circuit as a negative impedance. It is a sound output device.

  In one aspect of the present invention, the vibration measurement sensor is a vibration detection unit that detects an amplitude state of the diaphragm as the measurement value, and the correction control unit outputs a correction signal corresponding to the measurement value. A wearable sound output device that supplies the drive signal to the drive amplifier circuit and controls the drive signal so that the measured value has an amplitude corresponding to the input signal.

  In one aspect of the present invention, the vibration measuring sensor includes a current detecting unit that detects a current value of a driving current flowing through a coil in the driving unit, and a vibration detecting unit that detects an amplitude state of the diaphragm. The correction control unit performs a positive feedback of a correction signal corresponding to the measured value with respect to an input of the drive amplifier circuit, and equivalently sets the output signal of the drive amplifier circuit as a negative impedance to control the drive signal. And a correction signal corresponding to the measured value is supplied to the drive amplifier circuit, and the drive signal is controlled so that the measured value has an amplitude corresponding to the input signal.

  Further, according to one embodiment of the present invention, a measurement value indicating a vibration state of a diaphragm in a speaker is detected by a vibration measurement sensor, the diaphragm is vibrated by a driving unit, and vibration corresponding to an input signal is transmitted to the diaphragm. A drive signal supplied to the drive unit from a drive amplifier circuit, the vibration control unit obtains the vibration state of the vibration plate from a measurement value of the vibration measurement sensor, and drives the drive in accordance with the vibration state. This is a drive control method for a wearable audio output device that performs correction control of a signal.

  As described above, according to the present invention, without providing an air hole or a sound absorbing material in a housing, a mounting type that removes the influence of external noise and abnormal vibration of a speaker diaphragm due to air column resonance with high accuracy. It is possible to provide a drive control method for the sound output device and the wearable sound output device.

1 is a conceptual diagram illustrating a configuration example of a wearable sound output device using a drive control device according to a first embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a configuration example of a drive control device 20 according to the first embodiment in FIG. It is a conceptual diagram explaining the modification of the drive control device in this embodiment. It is a conceptual diagram showing the example of composition of the wearing type sound output device using the drive control device by a 2nd embodiment of the present invention. It is a conceptual diagram showing the example of composition of the wearing type sound output device using the drive control device by a 2nd embodiment of the present invention. It is a conceptual diagram showing the example of composition of the wearing type sound output device using the drive control device by a 3rd embodiment of the present invention.

<First embodiment>
Hereinafter, a wearable sound output device using the drive control device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing a configuration example of a wearable sound output device using a drive control device according to a first embodiment of the present invention. In the present embodiment, there are earphones and headphones as wearable sound output devices. However, in the following, an earphone (including a canal type) will be described as an example. The control for suppressing vibration (abnormal vibration) will be described. Also in the headphones, the control for suppressing the abnormal vibration of the diaphragm of the speaker is the same as that of the earphone described as an example.

In FIG. 1, the wearable acoustic output device 1 includes a housing 101, an earpiece 102, a diaphragm 103, a diaphragm holder 104, a diaphragm driving unit 105, a permanent magnet 106, a drive control device 20, and a vibration measurement sensor 204. Have. The speaker has a configuration including a diaphragm 103, a diaphragm holder 104, a diaphragm driving unit 105, and a permanent magnet 106.
With the above-described configuration, the diaphragm driving unit 105 provided on the diaphragm 103 is excited by the driving signal supplied from the drive control device 20, and the diaphragm driving unit 105 receives the electromagnetic force generated by the magnetic field generated by the permanent magnet 106. Based on this, the diaphragm 103 vibrates in the plate thickness direction to generate a sound corresponding to the acoustic signal.

  The vibration plate 103 is, for example, a plate-like member that emits sound, and is, for example, a thin film member made of a base material such as carbon or hard plastic. The diaphragm 103 is fixed to the housing 101 so as to be able to vibrate by a diaphragm holder 104, and as described above, the thickness of the diaphragm 103 is controlled by the drive control device 20 according to the excitation of the diaphragm driving unit 105. By vibrating in the direction, sound (acoustic sound) is radiated to a space perpendicular to the plate surface.

FIG. 2 is a conceptual diagram illustrating a configuration example of the drive control device 20 according to the first embodiment in FIG.
In FIG. 2, the drive control device 20 includes a drive amplifier circuit 201, an adder 202, a correction control unit 203, and a vibration measurement sensor 204.
The correction control unit 203 has a function of correcting the first input signal based on the measurement value, and includes each of the amplifier circuit 2031 and the voltage detection unit 2032.

  The diaphragm driving unit 105 has, for example, a configuration in which a coil 122 is wound around a magnetic body 121 as shown in FIG. 2. By supplying a driving current to the coil 122, a frequency and an amplitude corresponding to the driving current are supplied. The value is displaced in the direction of the magnetic field of the coil 122 with respect to the permanent magnet 106 in FIG. As a result, the diaphragm driving unit 105 transmits vibration due to relative displacement of the coil 122 with respect to the permanent magnet 106 to the diaphragm 103 to which the magnetic body 121 of the coil 122 is fixed. Accordingly, the diaphragm 103 vibrates in accordance with the amplitude of the vibration of the coil 122, and emits a sound (acoustic sound) corresponding to the amplitude of the plate surface and the frequency of the vibration. The resistor 120 indicates a resistance component of the coil 122 and has a resistance value R1.

The vibration measurement sensor 204 is, for example, a measurement resistor having a resistance value of R _C , and corresponds to a measurement value of a current flowing through the coil 122 corresponding to the drive current and a resistance value R _C when the current flows through itself. Output as voltage value of voltage drop.
The voltage detection unit 2032 reads a measurement value of the vibration measurement sensor 204 and outputs the measurement value to the amplification circuit 2031 as a measurement voltage value.

The amplifying circuit 2031 is a circuit that amplifies the measured voltage value by setting the transfer gain to β, amplifies (multiplies by β) the transfer gain β to the measured voltage value, and amplifies the measured voltage value. 2 is output to the adder 202. That is, the amplification circuit 2031 gives the transmission gain β for adjusting the positive feedback ratio to the measured voltage value, and feeds back the measured voltage value V1 to the drive amplifier 201 through the adder 202.
The adder 202 adds the measured voltage value V1 to which the transmission gain β is given and positively fed back to the first input signal Si1, and outputs the result to the drive amplifier circuit 201 as an added value V2.

The drive amplifier circuit 201 has a transfer gain of A, applies the transfer gain A to the added value V2 output from the adder 202 (multiplies the transfer gain by A), and supplies the resultant to the diaphragm driving unit 105 as a drive signal Vo.
Here, the relationship between the drive signal Vo and the first input signal Si1 in the drive control device 20 is expressed by the following equation (1).
Vo = A · Si1 · R1 / (R1 + (1-A · β) · _RC ) (1)
In the expression (1), by setting A · β> 1, the output impedance of the drive amplifier circuit 201 becomes equivalently (apparently) negative impedance. Therefore, the resistance value R1 of the resistor 120 of the coil 122 can be apparently reduced according to the magnitude of the negative impedance.

Therefore, in the case of R1 = − (1−A · β) · _RC , ideally, the influence of the resistance value R1 is eliminated, that is, the resistance value of the resistor 120 which is the resistance component of the coil 122 becomes “0”. , A · Si 1 as a drive signal Vo to the ideal coil 122.
On the other hand, when R1 <(1−A · β) · _RC , the correction control unit 203 oscillates, so that A · β is set so that R1 ≧ (1−A · β) · _RC .

  In general, in the wearable acoustic output device 1 such as an earphone, extra vibration (frequency and amplitude values, frequency and amplitude values, and the like) due to the influence of noise of external sound applied to the diaphragm 103 and disturbance (external force) due to air column resonance. That is, abnormal vibration) is added as an extra vibration component to the vibration of the diaphragm 103 corresponding to the first input signal Si1, thereby deteriorating the sound quality of the sound output emitted from the diaphragm 103 in the speaker.

  However, as in the configuration of the present embodiment described above, the measured value of the vibration measurement sensor 204 is given a predetermined transmission gain β and is positively fed back to the drive amplifier circuit 201, so that the output impedance of the drive amplifier circuit 201 is reduced. By controlling the impedance so as to have a predetermined negative impedance equivalently, the resistance value of the resistor 120 of the coil 122 can be apparently reduced. As a result, according to the present embodiment, in order to control the output impedance of the drive amplifier circuit 201 so as to have a predetermined negative impedance value, an extra vibration component that inhibits the vibration corresponding to the first input signal Si1 is used. The generated back electromotive force generated in the coil 122 of the diaphragm driving unit 105 can be reduced.

That is, according to the present embodiment, since the output impedance is controlled so as to be a negative impedance for reducing the back electromotive force, the noise of the external sound is generated with respect to the diaphragm 103 which causes the back electromotive force. An extra vibration component applied due to influence or disturbance (external force) due to air column resonance can be reduced. For this reason, according to the present embodiment, it is not necessary to use acoustic impedance as in the related art, the diaphragm 103 responds better to driving by the diaphragm driving unit 105, and the frequency characteristics of the vibration of the diaphragm 103 are improved. The sound quality of the sound output emitted from the diaphragm 103 can be improved.
In FIG. 2, a voltage corresponding to the current flowing through the coil 122 is detected by using a resistor as the vibration measurement sensor 204. As a modified example, a configuration may be adopted in which the current flowing through the coil 122 is measured by the vibration measurement sensor 204 instead of the resistance using a measurement coil.

FIG. 3 is a conceptual diagram illustrating a modified example of the drive control device according to the present embodiment. FIG. 3 shows a configuration in which the vibration measurement sensor 204 of FIG. 2 is replaced with a current sensor using a coil instead of a resistor.
For example, a current sensor of a current transformer is provided for the wiring that grounds one end of the coil 122. Then, the voltage detection unit 2032 reads the voltage corresponding to the current flowing through the coil 122, that is, the measurement value of the vibration measurement sensor 204, and outputs the voltage to the amplification circuit 2031 as the measurement voltage value.

Instead of the current transformer, a Hall element may be used as the vibration measurement sensor 204 to measure a voltage corresponding to a current flowing through the coil 122. At this time, the Hall element is disposed on the magnetic core provided on the wiring that grounds one end of the coil 122 in FIG.
Further, a pickup coil may be used as the vibration measurement sensor 204 and disposed near the coil 122, and the voltage induced in the pickup coil may be measured based on the strength (magnetic flux density) of the changing magnetic field of the coil 122.

<Second embodiment>
Hereinafter, a wearable sound output device using a drive control device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a conceptual diagram illustrating a configuration example of a wearable sound output device using a drive control device according to a second embodiment of the present invention.
The drive control device 20A includes a drive amplifier circuit 201, an adder 202A, a correction control unit 203, a vibration measurement sensor 204, an external sound filter 205, an internal sound filter 206, and a signal correction filter. The difference from the first embodiment is that each of the external sound filter 205, the internal sound filter 206, and the signal correction filter 207 is included in the configuration. Hereinafter, the configuration and operation of the drive control device according to the second embodiment will be described in terms of differences from the first embodiment.

FIG. 5 is a conceptual diagram illustrating a configuration example of a wearable sound output device using a drive control device according to a second embodiment of the present invention. The configuration different from the first embodiment is that each of the microphone 25 and the microphone 26 is provided.
The microphone 25 is provided on the outer surface 101S of the housing 101 in the wearable sound output device 1A. Then, the microphone 25 acquires an external noise signal as measurement data (sound waveform data) of the sound (external sound that becomes noise) near the wearable acoustic output device 1A, and converts the acquired external noise signal into the external sound filter. 205 is output.
The microphone 26 is provided on the inner surface 101B of the housing 101 in the wearable sound output device 1A. Then, the microphone 26 acquires an internal acoustic signal as measurement data of the sound in the outer ear output by the wearable acoustic output device 1A, and outputs the acquired internal acoustic signal to the internal sound filter 206.

  Referring back to FIG. 4, the external sound filter 205 acquires an external noise signal output from the microphone 25. Then, the external sound filter 205 generates an external noise cancel signal having a phase opposite to that of the external noise signal in order to remove an external noise signal affecting the diaphragm 103 (ANC control). Then, the external sound filter 205 performs a phase correction on the generated external noise cancellation signal so as to correspond to the phase of the first input signal Si1. The external sound filter 205 performs negative feedback to the drive amplifier circuit 201 via the adder 202A as an external noise cancellation signal after the phase correction.

The internal sound filter 206 acquires an internal sound signal output from the microphone 26. Then, the internal sound filter 206 generates a correction signal for correcting the internal acoustic signal to be a signal corresponding to the input signal. Then, the internal sound filter 206 performs phase correction on the generated correction signal so as to correspond to the phase of the first input signal Si1. The internal sound filter 206 provides a positive feedback of the phase-corrected correction signal to the drive amplifier circuit 201 via the adder 202A.
The signal correction filter 207 is a filter having an equalizer function for correcting (compensating) the frequency characteristics and phase of the first input signal Si1 supplied from the external device.

  The adder 202 </ b> A is supplied with the measured voltage value V <b> 1 to which the transmission gain β is given and positively fed back from the amplifier circuit 2031, the external noise cancel signal supplied from the external sound filter 205, and the internal sound filter 206. Each of the correction signals is added to the first input signal Si1 corrected by the signal correction filter 207, and is output to the drive amplifier circuit 201 as an added value V2.

According to the present embodiment, according to the present embodiment, the output impedance of the drive amplifier circuit 201 is controlled so as to be equivalent to a predetermined negative impedance. Since the component is suppressed and the acoustic impedance is not used unlike the conventional example, the response of the drive control by the control signal of the diaphragm 103 is improved.
Thus, according to the present embodiment, since no acoustic impedance is used for suppressing the extra vibration component, the noise of the external sound on the diaphragm 103 is obtained by the ANC process performed by the external sound filter 205. Can be effectively removed in real time.

  Similarly, according to the present embodiment, since the acoustic impedance is not used for suppressing the extra vibration component, the sound in the outer ear performed by the internal sound filter 206 corresponds to the first input signal Si1. The response of the control of the diaphragm 103 by the correction signal, which is performed for the purpose, is improved.

<Third embodiment>
Hereinafter, a wearable acoustic output device using the drive control device according to the third embodiment of the present invention will be described with reference to the drawings. The configuration of the wearable sound output device using the drive control device in the third embodiment is the same as that in FIG. In FIG. 1, the wearable sound output device 1 includes a drive control device 20B. Further, the drive control device 20B includes a correction control unit 203B and a vibration measurement sensor 204B.

  The vibration measurement sensor 204B is a vibration detection unit, and is installed at a predetermined position on the plate surface of the vibration plate 103, unlike the vibration measurement sensor 204 in the first embodiment, and the position of the installed vibration plate 103 Numerical values indicating the amount of displacement of the plate surface due to the vibration of are measured as measurement values. As the vibration measuring sensor 204B, any sensor such as an acceleration sensor and a speed sensor having a function of detecting the amount of displacement from a predetermined position on the plate surface of the diaphragm 103 may be used.

FIG. 6 is a conceptual diagram illustrating a configuration example of a wearable sound output device using a drive control device according to a third embodiment of the present invention. In FIG. 6, the drive control device 20B includes a drive amplifier circuit 201B, a correction control unit 203B, and the above-described vibration measurement sensor 204B.
The drive amplifier circuit 201B has a transfer gain of A, a first input signal Si1 is supplied to a positive input terminal (+), and a measurement signal (described later) corresponding to a measurement value of the vibration measurement sensor 204B is supplied to a negative input terminal (-). The measured voltage value V3) is supplied, and the driving signal Vo is supplied to the diaphragm driving unit 105 from the output terminal.

The correction control unit 203B includes a voltage detection unit 2032B and an amplification unit 2031B.
The voltage detection unit 2032B acquires, as a measured voltage value, a voltage value output from the vibration measurement sensor 204B and corresponding to the displacement amount of the plate surface of the diaphragm 103.
The amplification unit 2031B is a circuit having a transmission gain of β and amplifying the measured voltage value, amplifying the measured voltage value by adding the transmission gain β to the measured voltage value, and measuring the measured voltage value V3 (the correction signal in claim 3). ) Is output to the negative input terminal (-) of the drive amplifier circuit 201B.

  Accordingly, the drive control device 20B uses the drive amplifier circuit 201B so that the measured voltage value V3 fed back from the correction control unit 203B has a waveform corresponding to the waveform of the supplied first input signal Si1. That is, the measured voltage value V3 is positively fed back so that the plate surface of the diaphragm 103 oscillates in response to the first input signal Si1, and feedback control is performed on the drive signal Vo.

Further, the configuration of each of the external sound filter, the internal sound filter, and the signal correction filter in the second embodiment may be provided in the drive control device 20B of the third embodiment.
Thus, according to the third embodiment, since the acoustic impedance is not used as in the second embodiment, the noise of the external sound on the diaphragm 103 is obtained by the ANC process performed by the external sound filter 205. Can be effectively removed in real time.
Similarly, according to the third embodiment, as in the second embodiment, since the acoustic impedance is not used, the acoustic sound in the outer ear performed by the internal sound filter 206 is converted to the first input signal Si1. The response of the control of the diaphragm 103 by the correction signal, which is performed for the correspondence, is improved.

In each of the first, second, and third embodiments, observer control may be used in the correction control unit 203 or 203B.
For example, in the case of the third embodiment, the correction control unit 203B obtains a difference between the amplitude amount of the diaphragm 103 driven by the diaphragm driving unit 105 and the amplitude amount of the diaphragm model in the correction control unit 203B. The measured voltage value V3 is output to the negative input terminal (-) of the drive amplifier circuit 201B so as to reduce.

  As described above, by using the observer control, the drive amplifier circuit 201B is used to drive the drive signal so that the amplitude of the measured voltage value V3 fed back from the correction control unit 203B corresponds to the amplitude of the first input signal Si1. Since the feedback control of Vo is performed, the extra vibration component described in the first embodiment in the vibration based on the first input signal Si1 of the diaphragm 103 can be reduced. Therefore, according to the present embodiment, there is no need to use acoustic impedance as in the related art, and the diaphragm 103 has a better response to driving by the diaphragm driving unit 105, the frequency characteristics of vibration are improved, and vibration is improved. The sound quality of the acoustic output (acoustic sound) emitted from the plate 103 can be improved.

In each of the first embodiment, the second embodiment, and the third embodiment, a Kalman filter may be used for the correction control unit (203, 203B).
In this case, for example, the correction control unit (203, 203B) multiplies the difference between the measurement value observed immediately before and the measurement value predicted by the previously supplied measurement voltage value V3 by the Kalman gain γ. Then, the multiplication result is set to a measured voltage value V3 supplied to the negative input terminal (-) of the drive amplifier circuit 201B (or to the adder).

  In the first embodiment, the second embodiment, and the third embodiment, each of the vibration measuring sensors 204 and 204B is provided, and the driving current flowing through the coil 122 in the diaphragm driving unit 105 is provided by the vibration measuring sensor 204. And the vibration measurement sensor 204B detects the amplitude state of the diaphragm 103. Then, the correction control unit 203 feeds back a correction signal corresponding to the measurement value (measured voltage value V1) of the vibration measurement sensor 204 to the input of the drive amplifier circuit 201, and equivalently outputs the output of the drive amplifier circuit 201. The drive signal is controlled by setting the impedance to the negative impedance, and a correction signal corresponding to the measurement value (measurement voltage value V3) of the vibration measurement sensor 204B is supplied to the drive amplifier circuit 201, and the measurement value (measurement voltage value V3) is The drive signal may be controlled so as to have an amplitude corresponding to the first input signal Si1.

  A program for realizing the functions of the correction control unit 203 shown in FIGS. 2 and 3 and the correction control unit 203B shown in FIG. 6 in the present invention is recorded on a computer-readable recording medium, and recorded on this recording medium. By causing the computer system to read and execute the program thus set, control processing of the drive signal Vo for removing an extra vibration component of the diaphragm 103 may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The "computer system" also includes a WWW (World Wide Web) system provided with a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, programs that hold programs for a certain period of time are also included.

  Further, the above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

Although the embodiment of the present invention has been described above, the above embodiment is merely an example, and the present invention is not limited to the above embodiment, and may be implemented in various different forms within the scope of the technical idea. Needless to say, it's good.
Also, the scope of the present invention is not limited to the illustrated and described exemplary embodiments, but also includes all embodiments that provide equivalent advantages to those aimed at by the present invention. Furthermore, the scope of the present invention is not limited to the combination of features of the invention defined by the claims, but includes any desired combination of the particular features of all disclosed respective features.

  DESCRIPTION OF SYMBOLS 1 ... Wearable acoustic output device 20, 20B ... Drive control device 101 ... Housing 101B ... Inner surface 101S ... Outer surface Housing 102 ... Earpiece 103 ... Diaphragm 104 ... Diaphragm holder 105 ... Diaphragm driving part 106 ... Permanent magnet 120 ... Resistance 121 ... Magnetic body 122 ... Coils 201 and 201B ... Drive amplifier circuits 202 and 202A ... Adders 203 and 203B ... Correction control units 204 and 204B ... Vibration measurement sensor 205 ... External sound filter 206 ... Internal sound filter 207 ... Signal correction filter 2031, 2031B ... amplifying unit 2032, 2032B ... voltage detecting unit

Claims (5)

A vibration measurement sensor that detects a measurement value indicating a vibration state of the diaphragm in the speaker,
A driving unit that vibrates the diaphragm,
A drive amplifier circuit that supplies a drive signal that provides vibration corresponding to an input signal to the diaphragm, to the drive unit,
A correction control unit that obtains the vibration state of the diaphragm from the measurement value of the vibration measurement sensor and corrects and controls the drive signal in accordance with the vibration state. The vibration measurement sensor is a current detection unit that detects a current value of a drive current flowing through a coil in the drive unit in response to the drive signal, as the measurement value,
The correction control unit performs a positive feedback of a correction signal corresponding to the measured value with respect to an input of the drive amplifier circuit, and equivalently controls the drive signal with an output impedance of the drive amplifier circuit as a negative impedance. The wearable sound output device according to claim 1. The vibration measurement sensor is a vibration detection unit that detects an amplitude state of the diaphragm as the measurement value,
The mounting according to claim 1, wherein the correction control unit supplies a correction signal corresponding to the measurement value to the drive amplifier circuit, and controls the drive signal so that the measurement value has an amplitude corresponding to the input signal. Type sound output device. The vibration measurement sensor,
Current detection means for detecting a current value of a drive current flowing through a coil in the drive unit, and a vibration detection means for detecting an amplitude state of the diaphragm,
The correction control unit performs a positive feedback of a correction signal corresponding to the measured value with respect to an input of the drive amplifier circuit, and equivalently sets the output signal of the drive amplifier circuit as a negative impedance to control the drive signal. The wearable acoustic output device according to claim 1, further comprising: supplying a correction signal corresponding to the measured value to the drive amplifier circuit, and controlling the drive signal so that the measured value has an amplitude corresponding to the input signal. . A measurement value indicating a vibration state of the diaphragm in the speaker is detected by a vibration measurement sensor,
Vibrating the diaphragm by a driving unit,
A drive signal for giving a vibration corresponding to an input signal to the diaphragm is supplied from a drive amplifier circuit to the drive unit,
The vibration control unit obtains the vibration state of the diaphragm from the measurement value of the vibration measurement sensor and corrects and controls the drive signal in accordance with the vibration state.
A drive control method for a wearable sound output device.

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