JP2002078074A - Acoustic signal reproduction device and ear pad type electroacoustic transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce or eliminate noise caused in lead wires between ear pad type electroacoustic transducer such as a headphone and a power amplifier. SOLUTION: The polarity of either of left and right power amplifiers 5L, 5R placed to left and right acoustic signal lines is inverted and the polarity of the ear pad type electroacoustic transducer 1 at the line whose polarity is inverted is also inverted so as to cancel or attenuate noise produced on lead wires 2L and 2R between the left and right power amplifiers 5L, 5R and the ear pad type electroacoustic transducer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound signal reproducing device for listening to a sound signal of a headphone or the like and an ear-contact type electro-acoustic conversion device. The present invention relates to an audio signal reproducing device and an ear contact type electric conversion device capable of reducing or canceling noise leaking into a lead wire.

[0002]

2. Description of the Related Art Conventionally, there has been known an electronic apparatus which inverts a noise component contained in a predetermined component in various electric apparatuses and adds the inverted signal to a positive-phase signal to cancel the noise. For example, in Japanese Patent Application Laid-Open No. Hei 8-306033, an acoustic signal recorded on a track of a magnetic tape 30 as a recording medium is reproduced by a recording / reproducing head 31 as shown in FIG. are doing. This acoustic signal S ₁
Is a signal waveform shown in FIG. 6 (B), wherein the non-inverting output noise N _1, such as various shown in FIG. 6 (B) is mixed in the recording and reproducing head 31.

[0003] In this way, the acoustic signal S mixed with the noise N _1
1 is supplied to the amplifier 32, and the noise-mixed sound signal S ₁ + N ₁ is supplied to the adder 35.

On the other hand, like the recording / reproducing head 31, the dummy head 33 into which various noises are mixed is replaced with the recording / reproducing head 3
1 and are supplied to an adder 35 via an inverting amplifier 34. As shown in FIG.
Inverting output noise N ₂ is outputted as shown in (B).

Therefore, the adder 35 outputs the signal from the amplifier 32.
Non-inverted output noise N₁And inverted output from inverting amplifier 34
Noise N_TwoAre added by the adder 35, and the non-inverted output noise
Z N ₁And inverted output noise N_TwoAre subtracted from each other
Killed adder S₁Output signal has a noise component N₁, N_Two
Signal S from which is removed₁Only output
I have.

[0006]

In the above-described conventional configuration, noise generated on the input side of various electric circuits of the electric equipment such as the recording / reproducing head 31 is considered. However, noise cancellation processing is performed as shown in FIG.
No consideration is given to noise generated on the output terminal side after the output from the adder 35.

Now, as shown in FIG. 6C, the left and right audio signals L and R are input to the input side, for example, the line of the drive unit side L _ch of the recording / reproducing device 36 and R _{ch as} in FIG. 6A. to cancel a noise component N _in occurring in the line, connecting the L _ch side to the positive-phase amplifier 32, the input side which rests on the L _ch and R _ch left and right to connect the R _ch side reverse phase amplifier 34 of even the noise N _in is canceled, but the left and right output terminals T _L and T noise N _in the input side placed on the left and right audio signals S _L and S _R of the _R can be canceled each other, the output terminal T Take the _L and T _R are supplied to the ear contacting electroacoustic transducing means 1 such as a headphone, for example, the noise N _out intact left and right electroacoustic transducer of the headphones 1 mixed in the left and right lead wire 2L (2R) , And could not be reduced or canceled out.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is to solve the problem between an output end of an acoustic signal reproducing device or an ear contact type electro-acoustic transducer and an electro-acoustic transducer. It is an object of the present invention to provide a sound signal reproducing device and an ear-contact type electro-acoustic conversion device capable of reducing or canceling noise mixed in a lead wire of the present invention and reproducing a sound signal without noise for a listener.

[0009]

According to a first aspect of the present invention, there is provided an audio signal reproducing apparatus for reproducing left and right audio signals by an ear-contact type electroacoustic converting means through an amplifying means. One of the left and right amplifying means and the output thereof have a reversed phase, and the ear-contact type electroacoustic conversion means on the side having the opposite phase has an opposite characteristic. The noise generated in the lead wire between the means is reduced or canceled.

A second aspect of the present invention is the first aspect of the present invention, wherein an inverting amplifier is used for the amplifying means having the opposite phase.

According to a third aspect of the present invention, in the first aspect, an inverting circuit is connected in series to a non-inverting amplifier as an amplifying means having an inverted phase.

According to a fourth aspect of the present invention, in the first aspect, an inversion means is provided as an inverse characteristic conversion means of the ear contact type electroacoustic conversion means, or a coil of the ear contact type electroacoustic conversion means is wound. The direction of rotation or the polarity of the magnetic field generating means is reversed.

A fifth aspect of the present invention is an ear-contact type electro-acoustic transducer configured to reproduce right and left acoustic signals by electro-acoustic converting means via left and right amplifying means, wherein one of the left and right amplifying means and its output is provided. Are reversed in phase, and the electro-acoustic conversion means on the side having the opposite phase have reverse characteristics, so that noise generated in a lead wire between the left and right amplifying means and the electro-acoustic conversion means is reduced or canceled.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, an acoustic signal reproducing means is integrated with the ear contact type electroacoustic transducer.

According to the present invention, it is possible to obtain a device capable of reducing or canceling noise mixed in a lead wire of an ear-contact type electroacoustic transducer such as a portable small acoustic signal reproducing device or a headphone.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an audio signal reproducing apparatus and an ear contact type electroacoustic conversion apparatus according to the present invention will be described in detail with reference to FIGS.

The recording medium used in the audio signal reproducing apparatus of the present invention is a disk such as a CD (compact disk), an MD (mini disk), a DVD (digital video disk) or a magnetic tape such as a cassette tape or a DAT (digital audio tape). Tape, memory stick, PC
(Personal computer) An audio signal recorded in a semiconductor memory such as a card, or an audio signal source such as an electronic music distribution service distributed via the Internet such as TV broadcast, BS broadcast, cable broadcast, and EMD (Electronic Music Distribution). The present invention will be described as an audio signal reproducing device including a sound signal recording / reproducing device having at least a reproducing function and a recording function in a player capable of reproducing the transmitted audio signal.

Various portable terminal devices as shown in FIG. 5 can be considered as those in which the above-described acoustic signal reproducing device is built in a PDA (personal portable information terminal).

That is, in FIG. 5, 19 is a portable cassette recording / reproducing apparatus, and 20 is a CCD camera with a reproducing apparatus in which a recording / reproducing function is added to a CCD camera, and records and / or records a recording medium 26 such as a CD, a cassette, and a memory stick. And reproducible. Reference numeral 21 denotes a PDA to which a reproduction function is usually added. 22 is a GPS (Global Positioning) with a playback device
System), 23 is a neck phone with a memory stick player, 24 is a mobile phone with a recording / playback function, 25 is a portable Memory Stick playback device, and each of these mobile terminal devices is an ear-contact type electroacoustic conversion device such as headphones. 1
The audio signal recorded on the recording medium 26 can be recorded and / or reproduced.

In general, an electroacoustic transducer (hereinafter, referred to as a unit) is put on the ear, and headphones using a semicircular band are used to fix both units to the head, or FIG.
(B) a neckphone that hangs a semi-circular band as shown at 23 on the neck, and furthermore, inserts the unit directly into the ear canal,
Earphones that radiate acoustic signals into the ear canal and ear-hook type that hit the unit to both ears through ear-hook parts and eyeglasses,
In the present invention, a pair of left and right units such as a hook type and a phone having a fixed part as one body are used in the present invention.
Phone unit).

FIG. 1 shows an embodiment of an audio signal reproducing apparatus according to the present invention. In FIG. 1, a CD, a cassette tape, or the like is used as the recording medium 26. As the audio signal reproducing device 19, the cassette recording and reproducing device 19 shown in FIG. 5 is used.

In FIG. 1, reference numeral 3 denotes a drive unit for mounting and driving a cassette or CD of a recording medium 26 and extracting an audio signal via a head or an optical pickup. , And are amplified by output power amplifiers 5L and 5R via the RF unit 4. Here, the power amplifiers 5L and 5R are both positive-phase amplifiers, and an arbitrary R signal for, for example, a right channel is supplied to a phone jack 7 via an inverting circuit 6.
J. Similarly, the L signal for the left channel from the positive-phase amplifier 5L is supplied directly to the phone jack 7J.

The phone plug 7P is paired with the phone jack 7J to form a connector. The left and right acoustic signal transmission leads 2L and 2R connected to the phone plug 7P are connected to the phone unit 1.

The left and right electroacoustic converters of the phone unit 1 are of the conductive type or the capacitor type. The configuration of the conductive type which is generally frequently used is shown in an enlarged view of a portion A. In this example, an inversion circuit 8 is further provided on the right channel side where the inversion circuit 6 provided on the power amplifier 5R side of the audio signal reproducing device 19 is provided.

[0025] In the above configuration, the case where noise N _{ou t} the noise N _out is placed on the left and right audio signals by mixing the lead wire 2L and 2R between phone plug 7P and von unit 1 of FIG. 2 waveform This will be described with reference to FIG.

In the waveform of FIG. 2, the left and right acoustic signals L and R picked up from the recording medium 26 have the same amplification factor at the output sections of the power amplifiers 5L and 5R for the right-phase left and right channels. Both output positive-phase signal waveforms.

In the right channel, the R signal has its waveform inverted by the inverting circuit 6, so that the acoustic signals L and R at the output terminal of the power amplifier 5L and the output terminal of the inverting circuit 6 are shown in FIGS. 2A and 2B.
Output each other in opposite phase of the signal as shown in the acoustic signal L ₁ and -R ₁ in the left and right waveforms.

[0028] The mutually, is output via the jack 7J and phone plug 7P and right leads 2L and 2R by L ₁ and -R ₁ antiphase, the L signal for the left channel directly, units The -R ₁ signal for the right channel is supplied to the left channel coil, converted into a positive-phase R ₂ signal by the inverting circuit 8 and supplied to the right channel coil of the unit.

Therefore, the left and right acoustic signals in the phone unit 1 are supplied to the left and right units in the same phase as L ₂ and R _{2 in} FIGS. Above, the left and right channel sound signals are L
₂ and R ₂ can be heard.

On the other hand, noises LN and RN mixed into the lead wires 2L and 2R are L ₁ and L _{1 of the} left and right channels which are output with opposite polarities as shown in the waveforms of FIGS. 2 (C) and 2 (D).
And so that the rests phase on -R ₁ signal.

However, one of the noises LN and RN mounted on the lead wires 2L and 2R in phase is the photo unit 1
2A, the acoustic signal output of the phone unit of the noise RN placed on the lead 2R of the right channel is placed on the lead 2L of the left channel, like RN _out of FIG. 2D. The noise LN and the sound signal output LN _out of the phone unit 1 of the phone unit 1 are opposite in phase to each other and are added on the sense of hearing, so that the noises LN _out and RN _out are mutually canceled or reduced.

On the other hand, among the left and right power signals supplied to the phone plug 7P from the left and right power amplifiers 5L and 5R, the -R ₁ signal on the right channel side of the L ₁ signal and the -R ₁ signal having the opposite characteristics is the same. since the inverted by inverting circuit 8 audio signals from the phone unit 1 is listener can listen as an acoustic signal L ₂ and R ₂ stereo without being canceled.

FIG. 3 shows another embodiment of the present invention.
FIG. 3 is a system diagram of a main part when N and RN are removed or attenuated.

In the case of this embodiment, as a signal source of the acoustic signal, the acoustic data of EMD via the Internet is downloaded to the personal computer 9, and the acoustic data of the CD or the like is compressed by the voice compressing means in the personal computer, and is stored in the memory stick 10. A recorded recording medium is used.

As shown in FIG. 3B, the neckphone 23 with a memory stick player is integrated with the phone unit 1 in the reproducing apparatus. Although there is no 2R, the noise LN and RN from the amplifier and the nearby digital IC are likely to be mixed into the lead wires 2L 'and 2R' between the power amplifiers 5L and 5R and the phone unit 1, so that the noise LN and RN in this portion are canceled. Let it.

In FIG. 3, reference numeral 11 denotes a memory stick insertion unit, 12 denotes a memory readout circuit, 13 denotes a digital-analog conversion circuit (D / A), and L signals having a positive phase with each other via a D / A 13. And left and right power amplifier 5L
And 5R.

[0037] In this example, any example of the power amplifier 5L for one of the left channel constituted by the inverting amplifier circuit OP _1, constituting the power amplifier 5R for the right channel at the non-inverting amplifier OP _2. L signal at the output terminal of the inverting amplifier OP ₁ if Kakusure is output after being inverted as -L ₁ signal, R signal of the non-inverting amplifier OP ₂ is output as R ₁ the positive-phase signal at the non-inverting. Here, R ₁ and R ₂ are an input resistance and a feedback resistance.

On the other hand, in-phase noises LN and RN on lead wires 2L 'and 2R' are -L ₁ + LN and R ₁
+ RN is supplied to the left and right driving coils 14L and 14R of the phone unit 1.

Here, whether the left driving coil 14L and the right driving coil 14R are wound in the opposite direction or the polarity of the magnetic field generating magnet of the electrodynamic type phone unit 1 is opposite to that of FIG. Similarly, an inverting circuit 8 such as a switch is provided to invert the polarity of one channel.

As described above, the lead wires 2L 'and 2
The noises LN and RN on R 'have opposite phases to each other and are canceled or attenuated. On the other hand, the -L ₁ and R ₁ signals of the left and right sound signals whose phases have been inverted are inverted by the phone unit 1 to become L ₂ and R ₂ signals, and can be heard.

In the above embodiment, a terminal device having a recording and / or reproducing function as described in detail in FIG. 5 has been described as an acoustic signal reproducing device. However, the acoustic signal reproducing device of the present invention is shown in FIG. The clip adapter as shown in the above also belongs to the category of the audio signal reproducing device of the present invention.

FIGS. 4A and 4B show an EMD sound signal taken into the PDA 21 or the like, which is transmitted from the PDA 21 to the USB.
A clip adapter 15 connected by wire (Universal Serial Bus) or wireless such as Bluetooth is clipped in a pocket or the like as shown in FIG. This is the case.

[0043]

According to the portable audio signal reproducing apparatus and the ear-contact type electro-acoustic transducer of the present invention, the noise component mixed into the lead wire at the output end of the reproducing apparatus is canceled or reduced. It is possible, and it is also possible to use a longer lead wire from the power amplifier to the electroacoustic converter.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of an audio signal reproducing device and an ear contact type electro-acoustic conversion device of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the acoustic signal reproducing device and the ear-contact type electroacoustic transducer of the present invention.

FIG. 3 is a system diagram showing another embodiment of the audio signal reproducing device and the ear contact type electro-acoustic conversion device of the present invention.

FIG. 4 is an external view showing an example of an embodiment of an audio signal reproducing device according to the present invention.

FIG. 5 is an explanatory diagram of various embodiments of the audio signal reproducing device of the present invention.

6A and 6B are a system diagram and a waveform diagram illustrating a noise removal method of a conventional acoustic signal reproducing device.

[Explanation of symbols]

1 ear contact type electroacoustic transducer (phone unit), 3 drive, 5L, 5R power amplifier, 7
J, 7P phone jack and plug, 6,8 ° inversion circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04R 5/033 H04R 5/033 Z

Claims (6)

[Claims] 1. Left and right sound signals are passed through left and right amplifying means.
An audio signal reproducing apparatus configured to reproduce by the ear-contact type electro-acoustic conversion means, wherein one of the left and right amplifying means and the output thereof is in a reverse phase, and the ear-contact type on the side of the opposite phase is used. An acoustic signal reproducing apparatus, wherein an electroacoustic converting means has an inverse characteristic, and noise generated in a lead wire between the output of the left and right amplifying means and the ear contact type acoustic converting means is reduced or cancelled. 2. The audio signal reproducing apparatus according to claim 1, wherein an inverting amplifier is used for the amplifying means having the opposite phase. 3. The audio signal reproducing apparatus according to claim 1, wherein the amplifying means having the opposite phase connects an inverting circuit to an output stage of a non-inverting amplifier. 4. An inverting means is provided as an inverse characteristic converting means of said ear contact type electroacoustic converting means, or a winding direction of a coil of said ear contacting type electroacoustic converting means or a polarity of a magnetic field generating means is reversed. 4. The sound signal reproducing apparatus according to claim 1, wherein 5. An ear-contact type electro-acoustic transducer configured to reproduce left and right acoustic signals by left and right electro-acoustic converting means via left and right amplifying means, wherein one of the left and right amplifying means and one of its outputs are connected to each other. It is characterized in that the electro-acoustic conversion means on the side having the opposite phase has an opposite characteristic, and noise generated in a lead wire between the left and right amplifying means and the electro-acoustic conversion means is reduced or cancelled. Ear-contact type electroacoustic transducer. 6. An ear-contact type electro-acoustic transducer according to claim 5, wherein an acoustic signal reproducing means is integrated with said ear-contact type electro-acoustic transducer.