JP2003152483A - Automatic level control circuit - Google Patents
Automatic level control circuitInfo
- Publication number
- JP2003152483A JP2003152483A JP2001351124A JP2001351124A JP2003152483A JP 2003152483 A JP2003152483 A JP 2003152483A JP 2001351124 A JP2001351124 A JP 2001351124A JP 2001351124 A JP2001351124 A JP 2001351124A JP 2003152483 A JP2003152483 A JP 2003152483A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- time constant
- voltage
- constant circuit
- frequency signal
- 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.)
- Granted
Links
Landscapes
- Circuit For Audible Band Transducer (AREA)
- Control Of Amplification And Gain Control (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明はスーパーウーファー
等の低周波信号を扱うオーディオ機器に使用されるオー
トマチックレベルコントロール回路に関する。
【０００２】
【従来の技術】オーディオ機器で使用されているオート
マチックレベルコントロール回路（以下、略してＡＬＣ
回路とも称する。）は、簡単化の理由でフィードバック
方式によって音量レベルを一定に押え込む手段を採用す
る回路が一般的である。例えば、図３の回路図に示され
るＡＬＣ回路１０のように、入力ＩＮから入った低周波
信号Ｖｓは制御用のＦＥＴもしくはバイポーラトランジ
スタＱと抵抗で構成される可変減衰器１を通過してアン
プ３で増幅されて出力ＯＵＴに至るが、さらに検波回路
４にて検波された後に、抵抗Ｒ１とコンデンサＣ１で構
成される時定数回路５に入力され、その充電電圧Ｖ０を
バッファアンプ６を通して前記可変減衰器１に制御信号
Ｓとして入力するといったフィードバック型の回路構成
となっているのが一般的である。
【０００３】ところで、上記時定数回路５の時定数τ１
は取り扱う周波数に対して十分に大きくしないと検波さ
れた低周波信号のリップルが可変減衰器１の制御信号Ｓ
中に残り、歪みを発生させる原因となることが知られて
いる。
【０００４】したがって、スーパーウーファーのように
低い信号周波数（１５Ｈｚ〜）を取り扱うオーディオ装
置においては、時定数τ１を小さく設定することができ
ないことになる。
【０００５】ところが上記のような低周波信号Ｖｓを取
り扱うスーパーウーファーに大レベル信号が入力され、
前記ＡＬＣ回路１０によってレベルが抑圧された直後に
入力信号レベルが急激に小さくなってしまった場合、大
きな時定数τ１の時定数回路５のコンデンサＣ１が放電
するまでのしばらくの間、ＡＬＣ回路１０が復帰せずに
小さな入力信号に対しても減衰が懸かって無音のような
状態を作り出してしまうことがあった。
【０００６】そこでこれを改善することを目的に、図４
の回路図に示されるＡＬＣ回路２０のように、破線枠９
内の検波回路（ダイオードＤ１、Ｄ２、Ｄ３）と次数を
上げたＣＲ時定数回路兼バッファアンプの回路構成で生
成される制御信号Ｓ′を可変減衰器１に入力する方式が
提案され既に商品化されている。このＡＬＣ回路２０は
時定数回路の次数を上げてリップルの除去率を悪化させ
ることなく時定数を小さく抑えられるように改善したも
のである。
【０００７】
【発明が解決しようとする課題】しかし、上記破線枠９
内のような次数を上げた時定数回路の手段では、次数を
上げることでリップル除去率／時定数を改善できるが、
より高い性能を目指すと回路規模が大きくなりコストア
ップや実装面積の増大を引き起こすので現実的でない。
【０００８】本発明は上記事情に鑑みてなされたもので
あり、歪み性能を維持したまま大レベル入力後の復帰時
間を短くできるようにした全く新規な構成のＡＬＣ回路
を提供するものである。
【０００９】
【課題を解決するための手段】本発明は、フィードバッ
ク方式のオートマチックレベルコントロール回路におい
て、可変減衰器１と、前記可変減衰器１を通過させた低
周波信号Ｖｓを増幅するアンプ３と、増幅した低周波信
号Ｖ１を検波する２つの検波回路４ａ、４ｂと、検波さ
れた各低周波信号電圧Ｖ２、Ｖ２′でそれぞれ充電され
る短時定数回路１４及び放電加速スイッチ１９付きの長
時定数回路１５と、前記短時定数回路１４側の電圧Ｖ２
と前記長時定数回路１５側の電圧Ｖ４とを比較するレベ
ル比較器１７と、前記短時定数回路１４側の電圧Ｖ２に
対し前記長時定数回路１５側の電圧Ｖ２′が所定電位差
よりも大きい状態の継続時間が所定時間Ｔ１以上になる
と前記長時定数回路１５の放電加速スイッチ１９を導通
させるタイマ回路１８と、を備えるとともに、前記長時
定数回路１５側の電圧Ｖ３を前記可変減衰器１の制御信
号Ｓとして入力する構成を特徴とするオートマチックレ
ベルコントロール回路３０を提供することにより、上記
課題を達成する。
【００１０】
【発明の実施の形態】本発明に係るＡＬＣ回路の実施の
形態について図面に基づいて説明する。
【００１１】図１は本発明に係るＡＬＣ回路のブロック
図の例であり、図２は本発明に係る具体的なＡＬＣ回路
図の例である。
【００１２】先ず、図１に示される本発明のＡＬＣ回路
３０の実施の形態はフィードバック方式のＡＬＣ回路を
前提とする。その構成は図３の従来例で示したＡＬＣ回
路１０と比較すると、可変減衰器１及びアンプ３を共通
とするが、その他の図１における一点鎖線で囲まれた制
御信号Ｓを生成する回路部分３１は全く新規な回路構成
である。
【００１３】即ち、ＡＬＣ回路３０の入力ＩＮに入った
低周波信号Ｖｓは可変減衰器１を通過した後、アンプ３
で増幅されて出力ＯＵＴに至るが、さらに２つの検波器
４ａ、４ｂで検波され、検波後に一方は比較的短い時定
数τ２（０．０５秒程度）の短時定数回路１４を充電
し、他方は比較的長い時定数τ３（２０秒程度）の長時
定数回路１５を充電する。そして前記短時定数回路１４
側の電圧Ｖ２（＝充電電圧）と前記長時定数回路１５の
充電電圧Ｖ２′のバッファアンプ１６、レベルシフト１
１を経た電圧Ｖ４がこれらに接続されたレベル比較器１
７に入力される。レベル比較器１７の出力はタイマ回路
１８に接続されて前記短時定数回路１４の電圧Ｖ２に対
し前記長時定数回路１５側の電圧Ｖ２′が所定電位差Ｖ
ｄｅｆ（０．２Ｖ程度に設定）よりも大きい状態の継続
時間が所定時間Ｔ１以上になると前記長時定数回路１５
の放電加速スイッチ１９を導通させるように構成されて
いる。そして上記長時定数回路１５のバッファアンプ１
６を通した電圧Ｖ３が制御信号Ｓとして可変減衰器１に
入力される。
【００１４】より具体的には、図２のＡＬＣ回路３０の
回路図に示されるように、２つの検波回路４ａ、４ｂは
ダイオードＤ１とＤ２で構成され、短時定数回路１４は
抵抗Ｒ２（１０ＫΩ）とコンデンサＣ２（４．７μＦ）
によって構成され、長時定数回路１５は抵抗Ｒ３（４．
７ＭΩ）とコンデンサＣ３（４．７μＦ）によって構成
されている。また、バッファアンプ１６とレベル比較器
１７は汎用オペアンプで構成され、レベル比較器１７の
出力電圧はＨが＋１３Ｖ、Ｌが−１３Ｖを取る。また、
上記レベル比較器１７の後に接続されたタイマ回路１８
は２つのダイオードとコンデンサＣｔ（０．１μＦ）と
抵抗Ｒｔ（４．７ＭΩ）で構成されており、レベル比較
器１７が２つの時定数回路１４、１５の電圧差Ｖｄｅｆ
を検出してから長時定数回路１５の電荷を加速放電させ
るまでの時間を前記所定時間Ｔ１に相等するように時定
数が設定されている。そして、上記コンデンサＣｔの電
圧が長時定数回路１５に付加されている放電加速スイッ
チ１９のトランジスタのベースに接続されている。
【００１５】上記ＡＬＣ回路３０の動作は、（イ）音量
レベル（低周波信号Ｖｓ強度）が上昇中もしくは増加も
減少もしていない場合、もしくは僅かづつ減衰している
場合は、前記レベル比較器１７に入力される２つの電圧
Ｖ２、Ｖ４は近接した値となり、タイマ回路１８は働か
ず長時定数回路１５の時定数τ３に依存する充電電圧Ｖ
２′をバッファアンプ１６に通した電圧Ｖ３が制御信号
Ｓとして可変減衰器１に入力される。（ロ）音量レベル
が急速に減少した場合は、短時定数回路１４と長時定数
回路１５のそれぞれの電荷はそれぞれの時定数τ２、τ
３にしたがって放電していくため、短時定数回路１４側
の電圧Ｖ２よりも長時定数回路１５側の電圧Ｖ２′が大
きい値をとる。そしてこの電圧Ｖ２に対して電圧Ｖ２′
が所定電位差Ｖｄｅｆよりも大きい状態がある設定され
た時間Ｔ１だけ継続した場合は音量が急速に減衰したと
判定して、長時定数回路１５に設けられた放電加速スイ
ッチ１９を導通させ、長時定数回路１５のコンデンサＣ
３の電荷を急速に放電させる。すると長時定数回路１５
の電圧Ｖ２′は時定数τ３よりも速く下がり、そのバッ
ファアンプ１６を通した電圧Ｖ３の制御信号Ｓによって
可変減衰器１は減衰しない状態に速やかに復帰すること
ができる。
【００１６】なお、図１、図２中の回路例の中でレベル
比較器１７のプラス端子側入力部に設けられたレベルシ
フト１１は２つの短／長時定数回路１４、１５の電圧に
含まれるリップル成分を不感にする目的とＶｄｅｆを作
る目的で設けられている。
【００１７】以上のように本発明はフィードバック型の
ＡＬＣ回路の時定数回路について、低周波信号レベルの
変化（増加／一定／減少）を判定し、低周波信号レベル
の急激な減少時には、これを自動的に判定して時定数を
短く切り替える回路を付加することによって、歪み性能
を維持したまま大レベル入力後の復帰時間を短くするこ
とができるのである。
【００１８】
【発明の効果】本発明に係るＡＬＣ回路は上記のように
構成されているため、低周波信号を扱うフィードバック
型のＡＬＣ回路の時定数回路に、低周波信号レベルの変
化（増加／一定／減少）を判定し、信号レベルの急激な
減少時は時定数を短く切り替える回路を付加することに
よって、歪み性能を維持したまま大レベル入力後の復帰
時間を短くできるという優れた効果を有する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic level control circuit used for audio equipment such as a super woofer which handles low frequency signals. [0002] Automatic level control circuits (hereinafter abbreviated as ALCs) used in audio equipment.
Also called a circuit. ) Is generally a circuit that employs a means for keeping the volume level constant by a feedback method for simplification. For example, as in the ALC circuit 10 shown in the circuit diagram of FIG. 3, a low-frequency signal Vs input from an input IN passes through a control FET or a variable attenuator 1 composed of a bipolar transistor Q and a resistor to be amplified. While reaching the amplified output OUT 3, further after being detected by the detection circuit 4 is inputted to the time constant circuit 5 composed of a resistor R1 and the capacitor C1, the the charging voltage V 0 via the buffer amplifier 6 Generally, a feedback-type circuit configuration in which the control signal S is input to the variable attenuator 1 is provided. Incidentally, the time constant τ 1 of the time constant circuit 5
If the ripple of the detected low frequency signal is not sufficiently large with respect to the frequency to be handled, the control signal S of the variable attenuator 1
It is known that they remain inside and cause distortion. [0004] Thus, in the audio apparatus for handling low signal frequencies (15Hz~) as subwoofer it would not be able to set the time constant tau 1 small. However, a large-level signal is input to a super woofer that handles the low-frequency signal Vs as described above,
Wherein if the input signal level immediately after the level has been suppressed by the ALC circuit 10 has become rapidly decreases, while the up large time capacitor C1 of the time constant circuit 5 the time constant tau 1 is discharged, the ALC circuit 10 However, there is a case where a small input signal is attenuated without recovery and a state like silence is created. [0006] In order to improve this, FIG.
As shown in the ALC circuit 20 shown in the circuit diagram of FIG.
A method of inputting a control signal S 'generated by a detection circuit (diodes D1, D2, and D3) and a circuit configuration of a CR time constant circuit and a buffer amplifier having an increased order to a variable attenuator 1 has been proposed and already commercialized. Have been. The ALC circuit 20 is improved so that the order of the time constant circuit is increased so that the time constant can be kept small without deteriorating the ripple removal rate. [0007] However, the broken line frame 9
In the means of a time constant circuit with an increased order as shown in the above, the ripple removal rate / time constant can be improved by increasing the order,
Aiming at higher performance increases the circuit scale, causing an increase in cost and mounting area, which is not practical. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ALC circuit having a completely novel structure capable of shortening a recovery time after a large-level input while maintaining distortion performance. According to the present invention, there is provided a feedback type automatic level control circuit comprising: a variable attenuator 1; and an amplifier 3 for amplifying a low frequency signal Vs passed through the variable attenuator 1. two of the detection circuit 4a for detecting a low-frequency signal V 1 obtained by amplifying, 4b and the short time constant circuit 14 and with a discharge acceleration switch 19 is charged by the respective low frequency signal voltage V 2, V 2 ', which is detected And the voltage V 2 on the short time constant circuit 14 side.
The long-time and level comparator 17 for comparing the voltage V 4 of the time constant circuit 15 side, the short time constant circuit 14 side voltage V 2 'is predetermined potential difference of the long time constant circuit 15 side with respect to the voltage V 2 and provided with a, a timer circuit 18 the duration of the high state to conduct discharge acceleration switch 19 of the long time constant circuit 15 and becomes equal to or greater than the predetermined time period T1 than the voltage V 3 of the long time constant circuit 15 side The above object is achieved by providing an automatic level control circuit 30 characterized in that the automatic level control circuit 30 is configured to be input as a control signal S of the variable attenuator 1. An embodiment of an ALC circuit according to the present invention will be described with reference to the drawings. FIG. 1 is an example of a block diagram of an ALC circuit according to the present invention, and FIG. 2 is an example of a specific ALC circuit diagram according to the present invention. First, the embodiment of the ALC circuit 30 of the present invention shown in FIG. 1 is based on a feedback type ALC circuit. Its configuration is different from that of the ALC circuit 10 shown in the conventional example of FIG. 3 in that the variable attenuator 1 and the amplifier 3 are common, but other circuit parts for generating a control signal S surrounded by a chain line in FIG. 31 is a completely new circuit configuration. That is, the low frequency signal Vs input to the input IN of the ALC circuit 30 passes through the variable attenuator 1,
And the output OUT is amplified by the second detector 4a and 4b. After the detection, one of the detectors charges the short time constant circuit 14 having a relatively short time constant τ 2 (about 0.05 seconds). The other charges the long time constant circuit 15 having a relatively long time constant τ 3 (about 20 seconds). And the short time constant circuit 14
Buffer amplifier 16 of level V 1 (= charge voltage) and charge voltage V 2 ′ of long time constant circuit 15, level shift 1
Voltage V 4 that has passed through the 1 is connected to these level comparator 1
7 is input. The output of the level comparator 17 is connected to a timer circuit 18 so that the voltage V 2 ′ on the long time constant circuit 15 side with respect to the voltage V 2 of the short time constant circuit 14 has a predetermined potential difference V
When the continuation time of a state larger than def (set to about 0.2 V) is equal to or longer than a predetermined time T1, the long time constant circuit 15
Is made to conduct. The buffer amplifier 1 of the long time constant circuit 15
6 the voltage V 3 through the is input to the variable attenuator 1 as the control signal S. More specifically, as shown in the circuit diagram of the ALC circuit 30 in FIG. 2, the two detection circuits 4a and 4b are composed of diodes D1 and D2, and the short time constant circuit 14 is composed of a resistor R2 (10 KΩ). ) And capacitor C2 (4.7 μF)
The long time constant circuit 15 includes a resistor R3 (4.
7MΩ) and a capacitor C3 (4.7 μF). The buffer amplifier 16 and the level comparator 17 are composed of general-purpose operational amplifiers. The output voltage of the level comparator 17 is + 13V for H and -13V for L. Also,
Timer circuit 18 connected after the level comparator 17
Is composed of two diodes, a capacitor Ct (0.1 μF), and a resistor Rt (4.7 MΩ), and the level comparator 17 has a voltage difference V def between the two time constant circuits 14 and 15.
The time constant is set so that the time from the detection of the time to the accelerated discharge of the charge in the long time constant circuit 15 is equal to the predetermined time T1. The voltage of the capacitor Ct is connected to the base of the transistor of the discharge acceleration switch 19 added to the long time constant circuit 15. The operation of the ALC circuit 30 is as follows: (a) When the volume level (low-frequency signal Vs intensity) is increasing or not increasing or decreasing, or is attenuating little by little, the level comparator 17 , The two voltages V 2 and V 4 inputted to the timer circuit 18 are close to each other, the timer circuit 18 does not operate, and the charging voltage V depends on the time constant τ 3 of the long time constant circuit 15.
The voltage V 3 obtained by passing 2 ′ through the buffer amplifier 16 is input to the variable attenuator 1 as a control signal S. (B) When the volume level is rapidly reduced, the electric charges of the short time constant circuit 14 and the long time constant circuit 15 are respectively set to the time constants τ 2 and τ
3, the voltage V 2 ′ on the long time constant circuit 15 side becomes larger than the voltage V 2 on the short time constant circuit 14 side. Then, the voltage V 2 ′ with respect to this voltage V 2
Is longer than the predetermined potential difference V def for a set time T1, it is determined that the sound volume has rapidly decreased, and the discharge acceleration switch 19 provided in the long time constant circuit 15 is turned on. Capacitor C of time constant circuit 15
3 is discharged rapidly. Then the long time constant circuit 15
The voltage V 2 ′ falls faster than the time constant τ 3 , and the variable attenuator 1 can quickly return to a state where it is not attenuated by the control signal S of the voltage V 3 passed through the buffer amplifier 16. In the circuit examples shown in FIGS. 1 and 2, the level shift 11 provided at the input terminal on the plus terminal side of the level comparator 17 is included in the voltages of the two short / long time constant circuits 14 and 15. It is provided for the purpose of making the ripple component insensitive and generating V def . As described above, according to the present invention, the change (increase / constant / decrease) of the low frequency signal level is determined for the time constant circuit of the feedback type ALC circuit. By adding a circuit for automatically determining and switching the time constant to a short time, it is possible to shorten the recovery time after a large-level input while maintaining the distortion performance. Since the ALC circuit according to the present invention is configured as described above, the change (increase / decrease) in the low-frequency signal level is applied to the time constant circuit of the feedback-type ALC circuit that handles the low-frequency signal. (Constant / decrease), and by adding a circuit for switching the time constant short when the signal level suddenly decreases, there is an excellent effect that the recovery time after a large level input can be shortened while maintaining the distortion performance. .
【図面の簡単な説明】
【図１】本発明に係るＡＬＣ回路ブロック図の例であ
る。
【図２】本発明に係るＡＬＣ回路の具体的な回路図の例
である。
【図３】従来のＡＬＣ回路図の第１例である。
【図４】従来のＡＬＣ回路図の第２例である。
【符号の説明】
１ 可変減衰器
３ アンプ
４、４ａ、４ｂ 検波回路
６、１６ バッファアンプ
１４ 短時定数回路
１５ 長時定数回路
１７ レベル比較器
１８ タイマ回路
１９ 放電加速スイッチ
１０、２０、３０ ＡＬＣ回路
Ｓ 制御信号
τ１、τ２、τ３ 時定数
Ｖｓ 低周波信号BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of an ALC circuit block diagram according to the present invention. FIG. 2 is an example of a specific circuit diagram of an ALC circuit according to the present invention. FIG. 3 is a first example of a conventional ALC circuit diagram. FIG. 4 is a second example of a conventional ALC circuit diagram. [Description of Signs] 1 Variable attenuator 3 Amplifier 4, 4a, 4b Detection circuit 6, 16 Buffer amplifier 14 Short time constant circuit 15 Long time constant circuit 17 Level comparator 18 Timer circuit 19 Discharge acceleration switch 10, 20, 30 ALC Circuit S Control signal τ 1 , τ 2 , τ 3 Time constant Vs Low frequency signal
Claims (1)
ルコントロール回路において、可変減衰器と、前記可変
減衰器を通過させた低周波信号を増幅するアンプと、増
幅した低周波信号を検波する２つの検波回路と、検波さ
れた各低周波信号電圧でそれぞれ充電される短時定数回
路及び放電加速スイッチ付きの長時定数回路と、前記短
時定数回路側の電圧と前記長時定数回路側の電圧とを比
較するレベル比較器と、前記短時定数回路側の電圧に対
し前記長時定数回路側の電圧が所定電位差よりも大きい
状態の継続時間が所定時間以上になると前記長時定数回
路の放電加速スイッチを導通させるタイマ回路と、を備
えるとともに、前記長時定数回路側の電圧を前記可変減
衰器の制御信号として入力する構成を特徴とするオート
マチックレベルコントロール回路。Claims: 1. A feedback type automatic level control circuit, comprising: a variable attenuator, an amplifier for amplifying a low-frequency signal passed through the variable attenuator, and detecting the amplified low-frequency signal. Two detection circuits, a short time constant circuit charged with each detected low-frequency signal voltage, a long time constant circuit with a discharge acceleration switch, a voltage on the short time constant circuit side, and a long time constant circuit side And a level comparator for comparing the voltage of the long time constant circuit with the voltage of the short time constant circuit side when the duration of the state in which the voltage on the long time constant circuit side is larger than a predetermined potential difference becomes a predetermined time or more. And a timer circuit for turning on the discharge acceleration switch, and inputting the voltage of the long time constant circuit as a control signal of the variable attenuator. Tomatic level control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001351124A JP3899904B2 (en) | 2001-11-16 | 2001-11-16 | Automatic level control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001351124A JP3899904B2 (en) | 2001-11-16 | 2001-11-16 | Automatic level control circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003152483A true JP2003152483A (en) | 2003-05-23 |
| JP3899904B2 JP3899904B2 (en) | 2007-03-28 |
Family
ID=19163482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001351124A Expired - Fee Related JP3899904B2 (en) | 2001-11-16 | 2001-11-16 | Automatic level control circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3899904B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005348312A (en) * | 2004-06-07 | 2005-12-15 | Renesas Technology Corp | Electronic component for high frequency power amplification |
| JP2008022512A (en) * | 2006-07-12 | 2008-01-31 | Micro-Star Internatl Co Ltd | Sound volume control method |
| US7411456B2 (en) | 2004-08-24 | 2008-08-12 | Matsushita Electric Industrial Co., Ltd. | AGC circuit |
| NO20091518L (en) * | 2006-10-20 | 2009-05-18 | Dolby Lab Licensing Corp | Audio dynamic processing using a reset |
| JP2012010107A (en) * | 2010-06-24 | 2012-01-12 | Sumitomo Electric Ind Ltd | Electronic circuit |
-
2001
- 2001-11-16 JP JP2001351124A patent/JP3899904B2/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005348312A (en) * | 2004-06-07 | 2005-12-15 | Renesas Technology Corp | Electronic component for high frequency power amplification |
| US7443242B2 (en) | 2004-08-24 | 2008-10-28 | Matsushita Electric Industrial Co., Ltd. | AGC circuit |
| US7411456B2 (en) | 2004-08-24 | 2008-08-12 | Matsushita Electric Industrial Co., Ltd. | AGC circuit |
| US7907739B2 (en) | 2006-07-12 | 2011-03-15 | Micro-Star Int'l Co., Ltd. | Method of volume controlling |
| JP2008022512A (en) * | 2006-07-12 | 2008-01-31 | Micro-Star Internatl Co Ltd | Sound volume control method |
| NO20091518L (en) * | 2006-10-20 | 2009-05-18 | Dolby Lab Licensing Corp | Audio dynamic processing using a reset |
| JP2010507330A (en) * | 2006-10-20 | 2010-03-04 | ドルビー・ラボラトリーズ・ライセンシング・コーポレーション | Audio dynamics processing using reset |
| JP4940308B2 (en) * | 2006-10-20 | 2012-05-30 | ドルビー ラボラトリーズ ライセンシング コーポレイション | Audio dynamics processing using reset |
| TWI415481B (en) * | 2006-10-20 | 2013-11-11 | Dolby Lab Licensing Corp | Audio dynamics processing using a reset |
| US8849433B2 (en) | 2006-10-20 | 2014-09-30 | Dolby Laboratories Licensing Corporation | Audio dynamics processing using a reset |
| NO342161B1 (en) * | 2006-10-20 | 2018-04-09 | Dolby Laboratories Licensing Corp | Audio dynamic processing using a reset |
| EP2082480B1 (en) * | 2006-10-20 | 2019-07-24 | Dolby Laboratories Licensing Corporation | Audio dynamics processing using a reset |
| JP2012010107A (en) * | 2010-06-24 | 2012-01-12 | Sumitomo Electric Ind Ltd | Electronic circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3899904B2 (en) | 2007-03-28 |
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