JP4487911B2 - Conversation assist device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conversation assisting device capable of achieving a stable conversation even on the occurrence of a surrounding environmental change such as a temperature change. <P>SOLUTION: The conversation assisting device is provided with a temperature detection means and controls a characteristic of an amplifier on a temperature detected by the temperature detection means to be capable of achieving suppression of sound quality deterioration and howling even on the occurrence of the change in ambient temperature thereby achieving the stable conversation even in an internal space of a mobile apparatus such as an automobile wherein the temperature change is caused and a lot of noises exist. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a conversation assistance device used in an internal space of an automobile or the like.

FIG. 15 is a conceptual diagram showing the configuration of a conversation assistance device used in the interior space of a conventional mobile device such as an automobile, FIG. 16 is an example of a round gain frequency characteristic of a conventional conversation assistance device, and FIG. It is an example of the amplifier gain frequency characteristic of a conversation assistance apparatus.

In FIG. 15 , 1 is a rear microphone, 2 is a front amplifier, 3 is a front speaker, 4 is a front microphone, 5 is a rear amplifier, 6 is a rear speaker, 7 is a car, 8 is a front seat, and 9 is a rear seat.

  An example of the operation principle of the conversation assistance device will be described.

As shown in FIG. 15 , a case will be described in which a vehicle having a three-row seat having a large internal space is installed for the purpose of assisting conversation between the front seat 8 and the rearmost rear seat 9.

  In this case, two systems of microphones as sound collection means, amplifiers as amplification means, and speakers as electroacoustic conversion means are provided.

  That is, the front microphone 4 and the front speaker 3 are disposed in the vicinity of the front seat 8, the rear microphone 1 and the rear speaker 6 are disposed in the vicinity of the rear seat 9, and the microphones and speakers of each system are coupled by an amplifier. ing.

  That is, in one system, the voice of the passenger on the rear seat 9 is collected by the rear microphone 1, amplified by the front amplifier 2, and emitted from the front speaker 3 toward the driver or the passenger seat.

  Further, in the other system, the voice from the driver or the passenger seat is collected by the front microphone 4, amplified by the rear amplifier 5, and emitted from the rear speaker 6 toward the passenger on the rear seat 9.

  As described above, even in a noisy environment such as engine sound and running sound when riding a car, the sound collected by the microphone from each seat is amplified by the amplifier and emitted from the speaker. A clear voice conversation between the front seat 8 and the rear seat 9 is realized.

Here, the one-round gain frequency characteristic with respect to temperature change of the conversation assisting apparatus is as shown in FIG. 16 , and the gain and frequency characteristic change greatly with temperature change.

FIG. 17 shows the amplifier gain frequency characteristics of the conversation assisting device.

For example, Patent Document 1 is known as prior art document information related to the invention of this application.
JP 2002-51392 A

  The conventional conversation assistance device exhibits its effect stably in a constant environment, that is, in an environment where the ambient temperature, humidity and the like are kept constant.

  However, for mobile devices such as automobiles, it is difficult to keep the surrounding environment constant, and therefore, there is a problem that sound reproduced from a speaker deteriorates or howling occurs.

  As a principle of howling, the sound signal emitted from the speaker to the interior space of the automobile is collected again by the microphone, and howling occurs if the round-trip characteristic satisfies the oscillation condition.

  Factors that determine this round-trip characteristic include a microphone sensitivity characteristic, a speaker sound pressure characteristic, an amplifier gain characteristic, and an acoustic space characteristic.

  Among these elements, the microphone and the speaker have a vibration system and a support system, and the vibration system and the support system are particularly sensitive to the ambient temperature and have remarkable temperature characteristics.

  Therefore, depending on the ambient temperature, the sensitivity characteristic and the sound pressure characteristic change, and the round-trip characteristic changes, so that the sound quality is deteriorated, or howling occurs if the oscillation condition is satisfied.

  The present invention solves such a conventional problem, and can realize a conversation by clear voice even in a noisy environment such as an engine sound and a running sound when riding a car, and has excellent sound quality deterioration and howling suppression. The object is to provide an auxiliary device.

In order to solve the above-mentioned problems, the present invention provides a sound collecting means for converting sound into an electric signal and an electric signal of the sound collecting means in a conversation assisting device between a first conversation person and a second conversation person. And a first sound collecting means in the vicinity of the first conversation person. The amplifying means for amplifying the sound and the electroacoustic converting means for converting the electric signal amplified by the amplifying means into sound are used as one signal transmission system. And a second system of electroacoustic conversion means, and a second system of sound collection means and a first system of electroacoustic conversion means are arranged in the vicinity of the second conversation person. The first system and the second system are formed in both directions, and are generated due to changes in the sensitivity characteristics of the sound collecting means having temperature characteristics with respect to the ambient temperature and the sound pressure characteristics of the electroacoustic conversion means. In order to suppress howling, the temperature in the atmosphere where this conversation assisting device is located The sound collected by the sound collecting means of the first system by the temperature change sensed thereby is collected by the electroacoustic conversion means of the first system and the second system. The first system and the second system are set so that a sufficient howling margin is set even if the circuit gain frequency characteristic that is recirculated and reproduced by the electroacoustic conversion unit of the second system via the sound unit changes. The characteristics of the system amplifying means are controlled by analog control so as to follow the temperature sensed by the change in the resistance value of the temperature sensing means, thereby suppressing sound quality deterioration and howling .

As described above, the conversation assistance device according to the present invention suppresses howling caused by changes in the sensitivity characteristics of the sound collecting means having temperature characteristics with respect to the ambient temperature and the sound pressure characteristics of the electroacoustic conversion means. In addition, the temperature sensing means for sensing the temperature in the atmosphere where the conversation assisting device is arranged, and the sound collected by the sound collecting means of the first system due to the temperature change sensed thereby, Sufficient howling even if the one-round gain frequency characteristics to be recirculated and reproduced by the second system electroacoustic conversion means via the first system electroacoustic conversion means and the second system sound collection means are changed. By controlling the characteristics of the amplifying means of the first system and the second system so as to follow the temperature sensed by the resistance value change of the temperature sensing means so that a margin is set , Howling suppression It can be realized.

  Accordingly, it is possible to provide a conversation assistance device that can realize a clear voice conversation even in a noisy environment such as an engine sound and a running sound when riding a car, and is excellent in sound quality deterioration and howling suppression.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a conceptual diagram showing the configuration of a conversation assistance device used in the internal space of a mobile device such as an automobile of the present invention.

  In FIG. 1, 11 is a rear microphone, 12 is a front amplifier, 13 is a front speaker, 14 is a front microphone, 15 is a rear amplifier, 16 is a rear speaker, 17 is an automobile, 18 is a front seat, and 19 is a rear seat.

  Hereinafter, an example as an operation principle of this conversation assistance device will be described.

  As shown in FIG. 1, a case will be described in which an automobile having a three-row seat having a large internal space as in the conventional example is installed for the purpose of assisting conversation between the front seat and the rear seat.

  That is, it is a case where it installed for the purpose of assisting the conversation between the front seat 18 and the rearmost rear seat 19.

  The reason for installing at this position is that the two places are separated from each other, and the conversation is likely to be difficult due to various noises while the automobile is running.

  In this case, two systems of microphones as sound collection means, amplifiers as amplification means, and speakers as electroacoustic conversion means are provided.

  That is, the front microphone 14 and the front speaker 13 are disposed in the vicinity of the front seat 18, the rear microphone 11 and the rear speaker 16 are disposed in the vicinity of the rear seat 19, and the microphones and speakers of each system are coupled by an amplifier. ing.

  That is, in one system, the voice of the passenger on the rear seat 19 is collected by the rear microphone 11, amplified by the front amplifier 12, and emitted from the front speaker 13 toward the driver or the passenger seat.

  In the other system, the voice from the driver or passenger seat is collected by the front microphone 14, amplified by the rear amplifier 15, and emitted from the rear speaker 16 toward the passenger on the rear seat 19.

  In this way, by providing two systems, conversation can be smoothly realized in both directions.

Here, the conversation assisting device is provided with temperature sensing means. And it is set as the structure which implement | achieves sound quality degradation and howling suppression by controlling the characteristic of amplifier so that the temperature sensed by this temperature sensing means may be followed .

  That is, as shown in FIG. 2, in order to establish conversation assistance, the sound collected by the rear microphone 11 is amplified by the front amplifier 12 and emitted from the front speaker 13, and the sound collected by the front microphone 14 is collected. The sound is amplified by the rear amplifier 15 and emitted from the rear speaker 16.

  At this time, a signal transmission loop is formed, and a round-trip characteristic is established.

  Factors that determine this round-trip characteristic include the sensitivity characteristic of the microphone, the sound pressure characteristic of the speaker, the gain characteristic of the amplifier, the characteristic of the acoustic space, and the like, which are set to an optimum state under predetermined environmental conditions.

  Here, FIG. 3 shows the temperature characteristic of the microphone sensitivity, and FIG. 4 shows the temperature characteristic of the sound pressure frequency of the speaker.

  Usually, these predetermined environmental conditions are set by assuming the environmental conditions that exist in the interior space of automobiles, that is, temperature and humidity conditions, when the passengers ride in a car with ordinary passengers. Yes.

  Under this environmental condition, a predetermined howling margin is set as shown in FIG. 5 to take measures to prevent howling.

  However, in extreme cases when traveling with an actual automobile, the temperature change becomes as large as several tens of degrees, and howling may occur even if the howling margin is set sufficiently.

  This is due to the remarkable temperature characteristics of the vibration system and support system of the speaker and microphone.

  Depending on the ambient temperature, the compliance of the vibration system and the support system of the speaker and microphone, that is, the flexibility, changes, so that the circuit characteristics change, and the howling margin that has been set in advance is lowered, resulting in howling.

  Therefore, in order to suppress howling, a sufficient howling margin is set even if the ambient temperature changes and the compliance or flexibility of the vibration system or support system of the speaker or microphone changes, and the circuit characteristics change. Need to be.

Therefore, the temperature sensing means is provided for this conversation assistance device, to control the characteristics of the amplifier so as to follow the temperature sensed by the temperature sensing means, sufficient howling margin to one cycle characteristics due to temperature changes Is configured to be set.

  The control of the characteristics of the amplifier as the amplification means is realized by controlling the gain of the amplification means.

  FIG. 6 shows a loop gain frequency characteristic when the gain of the amplifier of the conversation assistance apparatus is changed, and FIG. 7 shows an amplifier gain frequency characteristic when the gain of the amplifier of the conversation assistance apparatus is changed.

  For example, this is a method of securing a howling margin by lowering the gain of an amplifier when the characteristic of a speaker or a microphone changes due to a temperature change, and the round-trip characteristic changes to reduce the howling margin.

  This amplifier gain control method can be easily implemented and can be realized at low cost.

  Generally, only the sensitivity of the microphone tends to change with respect to the temperature change, and the frequency characteristic of the speaker tends to change.

  Therefore, this amplifier gain control method is suitable for microphone control.

  Furthermore, in addition to controlling the gain of the amplifying means, it can also be realized by controlling the frequency characteristics of the amplifying means.

  For example, this is a method of securing the howling margin by changing the frequency characteristic of the amplifier when the characteristic of the speaker or the microphone is changed due to the temperature change and the rounding characteristic is changed and the howling margin is lowered.

  FIG. 8 shows a one-round gain frequency characteristic when the frequency characteristic of the amplifier of the conversation assistance device is changed, and FIG. 9 shows a characteristic when the gain and frequency characteristic of the amplifier of the conversation assistance device are changed.

  This method of controlling the frequency characteristics of the amplifier can also be easily implemented and can be realized at low cost.

  The method based on the frequency characteristic control of the amplifier is suitable for controlling the speaker.

  Furthermore, it is possible to simultaneously perform the above two methods to control both the gain and frequency characteristics of the amplifying means. In this case, it is possible to perform control with higher accuracy, and to secure a larger howling margin. it can.

The method for controlling the characteristics of the amplifier which is an amplifying unit has been described above. Next, the temperature sensing unit and the method for controlling the gain of the amplifier based on this temperature will be described.

10, FIG. 11, and FIG. 12 are circuit diagrams showing temperature sensing means and an example of a gain control method of the amplifier based on this temperature.

This temperature sensing means is configured using an element whose impedance value changes with temperature.

  This element is a temperature sensitive resistor, and can be realized by using a thermistor as one of them.

By constructing the temperature sensing means using this element, it can be implemented easily and can be realized at low cost.

And about the arrangement | positioning of this temperature sensing means, you may arrange | position in any of a sound collection means, an amplification means, an electroacoustic conversion means, or all of them.

When the temperature sensing means is provided in the sound collecting means, accurate control according to the change in the ambient temperature of the sound collecting means can be realized.

  Moreover, when it is provided in the electroacoustic conversion means, it is possible to realize accurate control according to changes in the ambient temperature of the electroacoustic conversion means.

  Normally, when provided in an amplifying means that is often arranged between the sound collecting means and the electroacoustic conversion means, it is possible to realize control according to changes in the ambient temperature of both the sound collecting means and the electroacoustic conversion means. It becomes.

  Furthermore, when all of the sound collecting means, the amplifying means, and the electroacoustic converting means are arranged, it is possible to realize more accurate and accurate control in accordance with changes in all these ambient temperatures.

  In this method, even if the ambient temperature of the automobile is constant, the temperature change from the sound collecting means, the amplifying means, and the electroacoustic conversion means itself, or the temperature from other parts in the vicinity where these are arranged is practically used. This is an optimal method for placement in automobiles where changes and the like occur frequently.

  Of course, the effect can be expected sufficiently even by a method in which the temperature detecting means is arranged in one place in order to give priority to the simplification of cost and configuration.

  Next, control of the frequency characteristics of the amplification means will be described.

FIGS. 13 and 14 are electronic circuit diagrams showing temperature sensing means and an example of a method for controlling frequency characteristics of an amplifier based on the temperature.

  The control of the frequency characteristics of the amplifying means can be performed with higher accuracy by controlling the characteristics in the vicinity of the lowest resonance frequency of the sound collecting means or the electroacoustic conversion means.

  This is because the vibration system and support system of the sound collecting means or the electroacoustic conversion means has a characteristic in the vicinity of the lowest resonance frequency that varies greatly depending on the ambient temperature.

  For this reason, by controlling the characteristics in the vicinity of the lowest resonance frequency, a large howling margin can be secured, and control with higher accuracy becomes possible.

  As another method, the frequency characteristic of the amplifying unit may be controlled by controlling the characteristic near the support resonance frequency of the sound collecting unit or the electroacoustic conversion unit.

  Also in this case, control with higher accuracy is possible by controlling the characteristics in the vicinity of the support resonance frequency, which usually varies greatly with the ambient temperature.

  This is also because the characteristics of the vibration system or support system of the sound collection means or electroacoustic conversion means vary greatly depending on the ambient temperature in the vicinity of the support resonance frequency.

  For this reason, by controlling the characteristics in the vicinity of the support resonance frequency, a large howling margin can be ensured, and control with higher accuracy is possible.

  In the above description, the minimum resonance frequency and the support resonance frequency greatly depend on the physical property value of the material used, that is, the compliance value, and the physical property value of these materials has a large temperature characteristic, that is, temperature dependency.

  Therefore, since the pattern of the frequency characteristics in the vicinity of the lowest resonance frequency and the support resonance frequency changes abruptly depending on the ambient temperature, it is very effective to control the frequency characteristics in the vicinity thereof.

  In addition, changes in the frequency characteristics in the vicinity of the minimum resonance frequency and the support resonance frequency due to the ambient temperature are dominated by the physical property values of the materials used, and thus these materials are made stable in temperature. It is also important to use.

These characteristics control the amplifying means is performed by all analog electronic circuit.

The analog electronic circuit can be easily carried out, it can be realized at a low cost in terms of cost compared with the digital circuitry.

Here, it is one of the analog electronic circuit, a configuration for controlling the gain constituted by the temperature sensing means and the resistor.

Also, there another analog electronic circuit, a structure to control the frequency characteristics composed of an operational amplifier and the temperature sensing means and the resistor and capacitor.

Further, at this time, by setting the resonance frequency of the electronic circuit within the range of 1 to 2 times the lowest resonance frequency of the electroacoustic conversion means at room temperature, a great effect in control can be exhibited.

  That is, for example, when the temperature shifts from room temperature to a low temperature, the vibration system or support system of the electroacoustic conversion means such as a speaker works in the direction in which the physical property value increases the hardness in terms of flexibility, that is, becomes hard, The resonance frequency increases.

  This is because the rising level is generally in the range of 1 to 2 times the frequency at normal temperature.

As described above, conversation assistance device according to the present invention, the temperature sensing means is provided, so as to follow the temperature sensed by the temperature sensing means, to control the gain and frequency characteristics of the amplifier, round characteristics by temperature By configuring so as not to change, it is possible to realize sound quality degradation and howling suppression.

  Accordingly, it is possible to provide a conversation assistance device that can realize a clear voice conversation even in a noisy environment such as an engine sound and a running sound when riding a car, and is excellent in sound quality deterioration and howling suppression.

Conversation assistance device according to the present invention, the temperature sensing means is provided, so as to follow the temperature sensed by the temperature sensing means, by controlling the characteristics of the amplifier, it is possible to realize the suppression of sound quality deterioration and howling It can be used in the interior space of mobile devices such as automobiles, and can be expected to be applied to residential spaces such as houses, condominiums, and offices.

The conceptual diagram which showed the structure of the conversation assistance apparatus used for the interior space of the motor vehicle in embodiment of this invention Conceptual diagram showing the configuration of the loop gain frequency characteristics of the conversation assist device Temperature characteristics of microphone sensitivity of the conversation assist device Temperature characteristics of sound pressure frequency of the speaker of the conversation assist device Characteristic diagram showing howling margin in one-round gain frequency characteristics of the same conversation assist device Loop gain frequency characteristic diagram when the gain of the amplifier of the conversation assist device is changed Amplifier gain frequency characteristics when the gain of the amplifier of the conversation assist device is changed Circular gain frequency characteristic diagram when the frequency characteristic of the amplifier of the conversation assist device is changed Characteristic diagram when the gain and frequency characteristics of the amplifier of the conversation assist device are changed Gain control circuit diagram of temperature sensing means and amplifier by temperature in an embodiment of the present invention Other gain control circuit diagram of amplifier with temperature sensing means and temperature Another gain control circuit diagram of amplifier by temperature sensing means and temperature Frequency characteristics control circuit diagram of amplifier by temperature sensing means and temperature Other frequency characteristic control circuit diagram of the temperature sensing means and amplifier by temperature The conceptual diagram which showed the structure of the conversation assistance apparatus used for the interior space of the conventional motor vehicle A graph of one-round gain frequency when the gain of the amplifier of the conventional conversation assist device is changed Amplifier gain frequency characteristics when the gain of the amplifier of the conventional conversation assist device is changed

DESCRIPTION OF SYMBOLS 11 Rear microphone 12 Front amplifier 13 Front speaker 14 Front microphone 15 Rear amplifier 16 Rear speaker 17 Car 18 Front seat 19 Rear seat

Claims (21)

In a conversation assisting device between a first conversation person and a second conversation person, sound collecting means for converting sound into an electric signal, amplification means for amplifying the electric signal of the sound collection means, and amplification means The electroacoustic conversion means for converting the amplified electric signal into sound is one signal transmission system, and the first system sound collecting means and the second system electroacoustic conversion means are in the vicinity of the first conversation person. And a second system of sound collecting means and a first system of electroacoustic conversion means are arranged in the vicinity of the second conversation person, and the first system and the second system are arranged between the conversation persons. In order to suppress howling caused by changes in the sensitivity characteristics of the sound collecting means having a temperature characteristic with respect to the ambient temperature and the sound pressure characteristics of the electroacoustic conversion means, while the system is bidirectionally formed. to, temperature sensing for sensing the temperature of the atmosphere this conversation assistance device is arranged Configure stage, due to a temperature change sensed by this, the first sound collected by sound collecting means lineages, collecting the first electro-acoustic conversion means of the system and the second system as sufficient howling margin through one round gain frequency characteristic to be reproduced is round in electro-acoustic conversion means of the second system by the change of the sound unit is set, the first line and the Conversation assistance device characterized by suppressing deterioration of sound quality and howling by analog control of characteristics of amplification means of second system so as to follow temperature sensed by change in resistance value of temperature sensing means . The conversation assistance apparatus according to claim 1, further comprising a plurality of signal transmission systems with a plurality of conversation persons. 3. A conversation assisting device configured to change the gain of the amplifying means to follow the temperature sensed by the temperature sensing means as characteristic control of the amplifying means according to claim 1. 3. A conversation assisting device configured to change the frequency characteristic of the amplifying means so as to follow the temperature sensed by the temperature sensing means as the characteristic control of the amplifying means according to claim 1. 3. A conversation assisting device configured to change both the gain and frequency characteristics of the amplifying means to follow the temperature sensed by the temperature sensing means as characteristic control of the amplifying means according to claim 1. 2. The conversation assisting apparatus according to claim 1, wherein an element whose impedance value changes with temperature is used as a temperature sensing means for a part of an element constituting an electronic circuit whose voltage changes following temperature change. A conversation assisting device in which an element whose impedance value changes with respect to the temperature according to claim 6 is a temperature sensitive resistor. The conversation assistance apparatus which used the thermistor for the element in which an impedance value changes with respect to the temperature of Claim 6. The conversation assisting device according to claim 1, wherein the temperature sensing means is provided in the vicinity of the sound collecting means so as to sense the temperature of the sound collecting means. The conversation assisting apparatus according to claim 1, wherein the temperature sensing means is provided in the vicinity of the amplifying means so as to sense the temperature of the amplifying means. The conversation assisting apparatus according to claim 1, wherein the temperature sensing means is provided in the vicinity of the electroacoustic conversion means so as to sense the temperature of the amplification means. The temperature sensing means is provided in the vicinity of the sound collecting means, in the vicinity of the amplifying means, and in the vicinity of the electroacoustic converting means so as to sense the temperature of each of the three means of the sound collecting means, the amplifying means, and the electroacoustic converting means. The conversation assistance device described. 5. A conversation assisting device that controls the frequency characteristics of the amplifying means according to claim 4 in the vicinity of the lowest resonance frequency of the sound collecting means or electroacoustic converting means. 5. A conversation assisting device that controls the frequency characteristics of the amplifying means according to claim 4 in the vicinity of the support resonance frequency of the sound collecting means or electroacoustic converting means. In order to control the characteristics of the amplifying means according to claim 1, an analog electronic circuit that divides the voltage by using a temperature-sensitive resistance element, a fixed resistor, and an operational amplifier that are temperature sensing means is configured, and the amplifying means is accompanied by a temperature change. Conversation assistance device configured to change the characteristics of the. Using an analog electronic circuit configured to connect a temperature-sensitive resistor as a temperature sensing means in parallel with one or both of two fixed resistors, the control voltage of the amplifier is changed by a temperature change. The conversation assisting device according to claim 15, which is configured to control the gain characteristic of the amplification means as a result. A temperature sensitive resistor as a temperature sensing means, a fixed resistor, a capacitor, and an operational amplifier constitute an analog electronic circuit for frequency band control to control the frequency characteristics of the amplifying means due to temperature change. Item 15. A conversation assisting device according to item 15. 18. A conversation assisting device in which the resonance frequency of the analog electronic circuit according to claim 17 is set within a frequency range of 1 to 2 times the lowest resonance frequency of the electroacoustic conversion means at room temperature. A mobile device equipped with the conversation assistance device according to claim 1. An automobile equipped with the conversation assistance device according to claim 1. The mobile device or automobile equipped with the conversation assisting device according to claim 1, which assists conversation between a passenger in the front row seat and a passenger in the rear seat.

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