JP2718030B2 - Auditory correction circuit - Google Patents
Auditory correction circuitInfo
- Publication number
- JP2718030B2 JP2718030B2 JP62121904A JP12190487A JP2718030B2 JP 2718030 B2 JP2718030 B2 JP 2718030B2 JP 62121904 A JP62121904 A JP 62121904A JP 12190487 A JP12190487 A JP 12190487A JP 2718030 B2 JP2718030 B2 JP 2718030B2
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- amplifier
- signal
- control
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は音響装置の小音量時の聴感上の信号を補正す
る聴感補正回路に関するものである。
従来の技術
近年、聴感補正回路は音量調整用減衰器の電子化の動
きの中でLSI化されている。
以下図面を参照しながら、上述した従来の聴感補正回
路の一例について説明する。
第２図は従来の聴感補正回路のラウドネス回路を示す
ものである。第２図において、１は全て減衰量を決定す
る抵抗である。２はコンデンサー３と共に聴感補正を行
なうための抵抗である。４は減衰器の出力を伝達するア
ナログスイッチである。減衰器は第１図に示す様に抵抗
とアナログスイッチで構成され、抵抗を直列にｎ個接続
し、その接続点から図の様にアナログスイッチを介して
出力に接続する。スイッチ40は減衰量０のときにオン状
態となる。また、スイッチ4n+1は減衰量が∞のときにオ
ン状態となる。更に、抵抗1mと1m+1の中間タップを設け
そこから抵抗２とコンデンサー３を直列接続し、アース
に落とすことによってラウドネス回路を構成している。
以上のように構成された聴感補正回路について、以下
その動作について説明する。
第２図の入力点に信号が入力されるとする。各スイッ
チ40〜4n+1は外部から指定され、それらの内ただ１個の
スイッチのみがオン状態となり、他の全てのスイッチは
オフ状態となる様に制御されている。
今スイッチ4m+k（ただし4m＜4m+k＜4n+1）がオン、他
が全てオフとなっているとする。また抵抗２の抵抗値を
Ｒ、コンデンサー３の容量をＣとするとこの回路の伝達
関数Ｇ（ω）は
となり第３図に示す様な周波数特性が得られ、小音量時
に低周波成分を中・高周波成分に比して持ち上げること
で聴感補正を行なうことができる。第３図では出力レベ
ルをパラメータとして上式の周波数特性を示している。
発明が解決しようとする問題点
しかしながら上記のような構成では、音量調整をする
ために、抵抗に接続されたアナログスイッチをオン，オ
フするため、そのアナログスイッチ開閉のためのショッ
クノイズが信号に混入するという問題点を有していた。
本発明は上記問題点にかんがみ、電圧制御増幅器を用
いることによってノイズを発生することなく、しかも上
記のように小音量時に低周波成分を中・高周波成分に比
して持ち上げることでラウドネス特性を有する良好な聴
感補正回路を提供するものである。
問題点を解決するための手段
上記問題点を解決するために本発明の聴感補正回路
は、制御電圧により主信号の減衰量を制御する第１の電
圧制御増幅器と、任意に設定した基準電圧値より第１の
電圧制御増幅器の制御電圧を減じた電圧を増幅する差動
増幅器と、主信号を入力して聴感補正のための信号を出
力するローパスフィルタと、ローパスフィルタの出力の
聴感補正のための信号を入力して差動増幅器の出力によ
り聴感補正のための信号の減衰量を制御する第２の電圧
制御増幅器と、第１の電圧制御増幅器の出力と第２の電
圧制御増幅器の出力とを加算する加算器とを備え、第１
の電圧制御増幅器の制御信号が任意に設定した基準電圧
より小で第１の電圧制御増幅器による主信号の減衰量が
大きいときに第２の電圧制御増幅器による聴感補正信号
の減衰量が小さく、かつ任意に設定した基準電圧値より
第１の電圧制御増幅器の制御電圧が大きいときは差動増
幅器の出力がなく第２の電圧制御増幅器は聴感補正のた
めの信号を出力しないように構成したものである。
作用
本発明は上述した構成によって、第１の電圧制御増幅
器の制御信号が任意に設定した基準電圧より小で第１の
電圧制御増幅器による主信号の減衰量が大きい小音量の
領域においては第２の電圧制御増幅器による聴感補正信
号の減衰量が小さいので、聴感補正信号が加わってラウ
ドネス効果をもたらし、かつ任意に設定した基準電圧値
より第１の電圧制御増幅器の制御電圧が大きいような大
音量の領域においては差動増幅器の出力がなく第２の電
圧制御増幅器は聴感補正信号を出力しないのでラウドネ
ス効果を生じないように作用し、かつ従来の構成のよう
なアナログスイッチがないためにノイズを発生すること
もない。
実施例
以下本発明の一実施例の聴感補正回路について、図面
を参照しながら説明する。第１図は本発明の実施例にお
けるラウドネスコントロール回路を示すものである。第
１図において1aは主信号の減衰量を調整するための第１
の電圧制御増幅器で、1bは補正信号用の第２の電圧制御
増幅器である。２は補正信号の周波数特性用ローパスフ
ィルター（LPF）で、３は5a,5b,5c,5dの抵抗と共に差動
増幅器を構成する増幅器、４は加算回路、６はダイオー
ド、７は差動増幅器の基準電圧である。上述の差動増幅
器３は図示のように基準電圧７を抵抗5cと5dで分圧して
任意に設定した基準電圧値から電圧制御増幅器1aの制御
電圧Vcを減じた値を増幅し、1bの電圧制御増幅器の増幅
度を制御して補正信号強度を調整する様にしてある。以
上の様に構成した聴感補正回路について第１図および第
４図を用いて説明する。
今、入力に信号を加え、電圧制御増幅器1aの減衰量を
調節するように制御電圧Vcが加えられている。主信号は
電圧制御増幅器1aの出力から加算回路４に加えられる。
一方、補正信号は主信号から分岐してLPF2を通ることに
よって低周波成分のみがその出力から1bの電圧制御増幅
器に加えられる。第１図に示すように基準電圧７を抵抗
5cと5dで分圧した任意の基準電圧Vrefより電圧制御増幅
器1aの制御電圧Vcを減じた電圧を差動増幅器３が増幅
し、その出力がダイオード６を介して電圧制御増幅器1b
を制御する。その結果電圧制御増幅器1bの出力である補
正信号は、第４図のように制御電圧Vcが任意に設定した
基準電圧Vrefより小で、主信号の減衰量が大きい小音量
のとき、電圧制御増幅器1bの減衰が小、すなわち補正信
号音量が大になるように制御され、制御電圧入力が任意
に設定した基準電圧値Vrefに近付いてくると差動増幅器
３の出力は次第に小になり電圧制御増幅器1bの減衰も次
第に大きく、すなわち補正信号音量も小になり、制御信
号入力がさらに大になり基準電圧値Vrefを越えると、差
動増幅器３の出力がなくなり聴感補正のための電圧制御
増幅器1bの補正信号の出力も得られなくなる。加算回路
４で前述の主信号と補正信号とが加算されて、第３図の
様な特性を得る。
以上の様に本実施例によれば、基準電圧を抵抗で任意
に分割して設定した基準電圧値より第１の電圧制御増幅
器の制御電圧を減じた電圧を差動増幅器に加えて増幅
し、この差動増幅器の出力を第２の電圧制御増幅器に加
えて聴感補正のための信号の減衰量を制御し、この出力
信号を第１の電圧制御増幅器の出力に加えることによっ
て、聴感補正をかけ始める音量位置を任意に設定でき、
その任意の設定音量位置以上の大音量時には補正回路を
働かないように、したがってラウドネス効果を生じない
ようにでき、電子制御可能で全く制御ノイズの出ないラ
ウドネスコントロールの聴感補正回路を構成することが
できる。
発明の効果
以上の様に本発明は、制御電圧により主信号の減衰量
を制御する第１の電圧制御増幅器と、任意に設定した基
準電圧値より第１の電圧制御増幅器の制御電圧を減じた
電圧を増幅する差動増幅器と、主信号を入力して聴感補
正のための信号を出力するローパスフィルタと、ローパ
スフィルタの出力の聴感補正のための信号を入力して差
動増幅器の出力により聴感補正のための信号の減衰量を
制御する第２の電圧制御増幅器と、第１の電圧制御増幅
器の出力と第２の電圧制御増幅器の出力とを加算する加
算器とを備えたことにより、聴感補正をかけ始める音量
位置を任意に設定でき、その任意の設定音量位置以上の
大音量時には補正回路を働かないように、したがってラ
ウドネス効果を生じないようにでき、電子制御可能で、
しかも制御ノイズのない良好な聴感補正回路を提供する
ものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audibility correction circuit for correcting an audibility signal when a sound device has a low volume. 2. Description of the Related Art In recent years, an audibility correction circuit has been implemented as an LSI in the course of computerization of a volume adjusting attenuator. Hereinafter, an example of the above-described conventional audibility correction circuit will be described with reference to the drawings. FIG. 2 shows a loudness circuit of a conventional audibility correction circuit. In FIG. 2, 1 is a resistor for determining the amount of attenuation. Reference numeral 2 denotes a resistor for performing audibility correction together with the condenser 3. Reference numeral 4 denotes an analog switch for transmitting the output of the attenuator. The attenuator is composed of a resistor and an analog switch as shown in FIG. 1, n resistors are connected in series, and the connection point is connected to the output through an analog switch as shown in the figure. The switch 40 is turned on when the attenuation is zero. Further, the switch 4n + 1 is turned on when the amount of attenuation is ∞. Further, an intermediate tap between the resistors 1 m and 1 m + 1 is provided, and the resistor 2 and the capacitor 3 are connected in series from the tap and dropped to ground to form a loudness circuit. The operation of the audibility correction circuit configured as described above will be described below. Assume that a signal is input to the input point in FIG. Each of the switches 40 to 4n + 1 is externally designated, and only one of the switches is controlled to be on, and all other switches are controlled to be off. It is assumed that the switch 4 m + k (4 m <4 m + k <4 n + 1 ) is on and all others are off. When the resistance value of the resistor 2 is R and the capacitance of the capacitor 3 is C, the transfer function G (ω) of this circuit is A frequency characteristic as shown in FIG. 3 is obtained, and the auditory sensation can be corrected by raising the low frequency component in comparison with the middle and high frequency components when the sound volume is low. FIG. 3 shows the frequency characteristic of the above equation using the output level as a parameter. Problems to be Solved by the Invention However, in the above configuration, an analog switch connected to a resistor is turned on and off in order to adjust the volume, so that a shock noise for opening and closing the analog switch is mixed in the signal. Had the problem of doing so. In view of the above problems, the present invention has a loudness characteristic by using a voltage controlled amplifier without generating noise, and by raising a low frequency component in comparison with a medium / high frequency component at a low volume as described above. It is intended to provide a good audibility correction circuit. Means for Solving the Problems In order to solve the above problems, an audibility correction circuit according to the present invention comprises a first voltage control amplifier for controlling the amount of attenuation of a main signal by a control voltage, and an arbitrarily set reference voltage value. A differential amplifier for amplifying a voltage obtained by reducing the control voltage of the first voltage control amplifier, a low-pass filter for inputting a main signal and outputting a signal for audibility correction, and for audibility correction of the output of the low-pass filter A second voltage controlled amplifier for controlling the attenuation of a signal for auditory sensation correction based on the output of the differential amplifier and the output of the first voltage controlled amplifier and the output of the second voltage controlled amplifier. And an adder for adding
When the control signal of the voltage controlled amplifier is smaller than the arbitrarily set reference voltage and the amount of attenuation of the main signal by the first voltage controlled amplifier is large, the amount of attenuation of the audibility correction signal by the second voltage controlled amplifier is small, and When the control voltage of the first voltage control amplifier is higher than an arbitrarily set reference voltage value, the differential amplifier does not output and the second voltage control amplifier does not output a signal for audibility correction. is there. According to the present invention, with the above-described configuration, the second voltage is controlled in a low volume region where the control signal of the first voltage controlled amplifier is smaller than the arbitrarily set reference voltage and the attenuation of the main signal by the first voltage controlled amplifier is large. The amount of attenuation of the audibility correction signal by the voltage control amplifier is small, so that the audibility correction signal is added to produce a loudness effect, and the control voltage of the first voltage control amplifier is larger than an arbitrarily set reference voltage value. In the region (2), there is no output of the differential amplifier, and the second voltage control amplifier does not output the audibility correction signal, so that the loudness effect does not occur. Also, since there is no analog switch as in the conventional configuration, noise is reduced. It does not occur. Embodiment An audibility correction circuit according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a loudness control circuit according to an embodiment of the present invention. In FIG. 1, reference numeral 1a denotes a first signal for adjusting the attenuation of the main signal.
And 1b is a second voltage control amplifier for the correction signal. 2 is a low-pass filter (LPF) for the frequency characteristic of the correction signal, 3 is an amplifier that constitutes a differential amplifier together with resistors 5a, 5b, 5c and 5d, 4 is an addition circuit, 6 is a diode, and 7 is a differential amplifier. Reference voltage. The differential amplifier 3 described above divides the reference voltage 7 by resistors 5c and 5d as shown in the figure and amplifies a value obtained by subtracting the control voltage Vc of the voltage control amplifier 1a from an arbitrarily set reference voltage value. The amplification degree of the control amplifier is controlled to adjust the correction signal strength. The audibility correction circuit configured as described above will be described with reference to FIG. 1 and FIG. Now, a control voltage Vc is applied so as to apply a signal to the input and adjust the amount of attenuation of the voltage control amplifier 1a. The main signal is applied to the addition circuit 4 from the output of the voltage control amplifier 1a.
On the other hand, the correction signal branches off from the main signal and passes through the LPF 2 so that only the low-frequency component is applied from its output to the voltage-controlled amplifier 1b. As shown in FIG.
The differential amplifier 3 amplifies a voltage obtained by subtracting the control voltage Vc of the voltage control amplifier 1a from an arbitrary reference voltage Vref divided by 5c and 5d, and outputs the voltage via the diode 6 to the voltage control amplifier 1b.
Control. As a result, when the control signal Vc is lower than the arbitrarily set reference voltage Vref and the attenuation of the main signal is small, as shown in FIG. When the control voltage input approaches an arbitrarily set reference voltage value Vref, the output of the differential amplifier 3 gradually decreases and the voltage control amplifier 1b decreases. When the attenuation of 1b gradually increases, that is, the volume of the correction signal also decreases, and when the control signal input further increases and exceeds the reference voltage value Vref, the output of the differential amplifier 3 is lost and the voltage control amplifier 1b for audibility correction is used. The output of the correction signal cannot be obtained. The above-described main signal and correction signal are added by the adder circuit 4 to obtain a characteristic as shown in FIG. As described above, according to the present embodiment, a voltage obtained by subtracting the control voltage of the first voltage control amplifier from the reference voltage set by dividing the reference voltage arbitrarily by the resistor is added to the differential amplifier, and the voltage is amplified. The output of this differential amplifier is applied to a second voltage controlled amplifier to control the amount of attenuation of a signal for auditory sensation correction, and the output signal is added to the output of the first voltage controlled amplifier to apply auditory sensation correction. You can arbitrarily set the starting volume position,
It is possible to configure a loudness control audibility correction circuit that is electronically controllable and does not generate any control noise, so that the correction circuit does not operate at a loud volume higher than the arbitrary set volume position, so that the loudness effect does not occur. it can. As described above, according to the present invention, the control voltage of the first voltage control amplifier for controlling the attenuation of the main signal by the control voltage and the control voltage of the first voltage control amplifier are reduced from an arbitrarily set reference voltage value. A differential amplifier that amplifies the voltage, a low-pass filter that inputs the main signal and outputs a signal for auditory sensation, and a signal that inputs the signal for auditory sensation correction of the output of the low-pass filter and the audibility of the output of the differential amplifier By providing a second voltage controlled amplifier for controlling the amount of attenuation of the signal for correction, and an adder for adding the output of the first voltage controlled amplifier and the output of the second voltage controlled amplifier, The volume position at which correction is to be started can be set arbitrarily, so that the loudness effect does not work when the volume is higher than the arbitrary set volume position, so that the loudness effect does not occur, and electronic control is possible.
Moreover, the present invention provides a good audibility correction circuit free of control noise.
【図面の簡単な説明】
第１図は本発明の実施例における聴感補正回路の回路
図、第２図は従来の聴感補正回路の回路図、第３図は第
２図の回路の出力周波数特性図、第４図は第１図の電圧
制御増幅器1a,1bの動作説明図である。
1a,1b……電圧制御増幅器、２……ローパスフィルタ
ー、３……差動増幅器、４……加算回路、5a,5b,5c,5d
……抵抗、６……ダイオード、７……基準電圧源。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an audibility correction circuit according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a conventional audibility correction circuit, and FIG. 3 is an output frequency characteristic of the circuit of FIG. FIG. 4 is an explanatory diagram of the operation of the voltage controlled amplifiers 1a and 1b of FIG. 1a, 1b: voltage-controlled amplifier, 2: low-pass filter, 3: differential amplifier, 4: addition circuit, 5a, 5b, 5c, 5d
... Resistance, 6 Diode, 7 Reference voltage source.
Claims (1)
圧制御増幅器と、 任意に設定した基準電圧値より前記第１の電圧制御増幅
器の制御電圧を減じた電圧を増幅する差動増幅器と、 主信号を入力して聴感補正のための信号を出力するロー
パスフィルタと、 前記ローパスフィルタの出力の聴感補正のための信号を
入力して前記差動増幅器の出力により前記聴感補正のた
めの信号の減衰量を制御する第２の電圧制御増幅器と、 前記第１の電圧制御増幅器の出力と前記第２の電圧制御
増幅器の出力とを加算する加算器とを備え、 前記第１の電圧制御増幅器の制御信号が前記任意に設定
した基準電圧より小で前記第１の電圧制御増幅器による
主信号の減衰量が大きいときに前記第２の電圧制御増幅
器による前記聴感補正信号の減衰量が小さく、かつ前記
任意に設定した基準電圧値より前記第１の電圧制御増幅
器の制御電圧が大きいときは前記差動増幅器の出力がな
く前記第２の電圧制御増幅器は前記聴感補正のための信
号を出力しないように構成したことを特徴とする聴感補
正回路。(57) [Claims] A first voltage control amplifier for controlling an attenuation amount of a main signal by a control voltage; a differential amplifier for amplifying a voltage obtained by subtracting a control voltage of the first voltage control amplifier from an arbitrarily set reference voltage value; A low-pass filter for inputting a signal and outputting a signal for audibility correction; and a signal for inputting a audibility correction of an output of the low-pass filter, and an attenuation of the signal for audibility correction by an output of the differential amplifier. A second voltage-controlled amplifier for controlling the amount; and an adder for adding the output of the first voltage-controlled amplifier and the output of the second voltage-controlled amplifier, and controlling the first voltage-controlled amplifier. When the signal is smaller than the arbitrarily set reference voltage and the amount of attenuation of the main signal by the first voltage controlled amplifier is large, the amount of attenuation of the audibility correction signal by the second voltage controlled amplifier is small, and When the control voltage of the first voltage control amplifier is higher than the arbitrarily set reference voltage value, there is no output of the differential amplifier and the second voltage control amplifier does not output the signal for audibility correction. An auditory sense correction circuit characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62121904A JP2718030B2 (en) | 1987-05-19 | 1987-05-19 | Auditory correction circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62121904A JP2718030B2 (en) | 1987-05-19 | 1987-05-19 | Auditory correction circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63286015A JPS63286015A (en) | 1988-11-22 |
| JP2718030B2 true JP2718030B2 (en) | 1998-02-25 |
Family
ID=14822787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62121904A Expired - Fee Related JP2718030B2 (en) | 1987-05-19 | 1987-05-19 | Auditory correction circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2718030B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11330876A (en) | 1998-05-15 | 1999-11-30 | Nec Corp | Voltage-controlled amplifier circuit |
| WO2002013376A2 (en) | 2000-08-03 | 2002-02-14 | Broadcom Corporation | Method and circuit for a dual supply amplifier |
| JP4825115B2 (en) * | 2006-11-15 | 2011-11-30 | 新日本無線株式会社 | Loudness circuit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57117820U (en) * | 1981-01-13 | 1982-07-21 |
-
1987
- 1987-05-19 JP JP62121904A patent/JP2718030B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63286015A (en) | 1988-11-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |