CN1112761C - 重放音频信号的频率特性补偿装置 - Google Patents
重放音频信号的频率特性补偿装置 Download PDFInfo
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- CN1112761C CN1112761C CN97102419A CN97102419A CN1112761C CN 1112761 C CN1112761 C CN 1112761C CN 97102419 A CN97102419 A CN 97102419A CN 97102419 A CN97102419 A CN 97102419A CN 1112761 C CN1112761 C CN 1112761C
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- signal
- frequency
- replay
- audio signal
- amplitude limiter
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Classifications
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G9/00—Combinations of two or more types of control, e.g. gain control and tone control
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
- H03K5/22—Circuits having more than one input and one output for comparing pulses or pulse trains with each other according to input signal characteristics, e.g. slope, integral
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/22—Signal processing not specific to the method of recording or reproducing; Circuits therefor for reducing distortions
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/08—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements
- H03F1/083—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements in transistor amplifiers
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- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
- Circuit For Audible Band Transducer (AREA)
Abstract
一种重放音频信号频率特性补偿装置,在重放音频信号时从高频区的重放信号中除去噪声,接着将去除噪声的重放信号加重,从而提高了重放信号的频率特性。该装置包括:一高通滤波器,用来只使重放信号的高频成分通过;一限幅器,它从经所述高通滤波的重放信号中截除两预定电平之间的信号而产生限幅信号;一加法器,用于将所述限幅信号叠加于重放信号上以加重高频信号。
Description
技术领域
本发明涉及一种音频信号重放装置,具体地说,涉及在音频信号重放期间排除重放信号在高频区中的噪声然后加重已消除噪声的重放信号,以补偿重放音频信号频率特性的装置。
背景技术
图1示出录音信号电平与重放输出信号电平之间的关系。在此场合下,录音电平超过一定值时,便破坏了录音信号电平与重放输出信号电平之间的线性关系。也就是说,录音信号电平提高到一定值以上时,便在重放中产生失真。并且,因录音信号电平与信噪(S/N)比成正比,录音信号电平降低时,S/N比降低。
图2示出录音中一均衡器的频率特性。由图可见,在一定频率以上的高频区,增益与频率成正比上升。
因此,在音频信号的常规录制技术中把录音电平提高到不使录音信号饱和的量值,从而提高S/N比而无信号失真。
在传统的音频信号录制装置中,尽管录音期间高频成分在均衡器中得到加重,但重放时由于磁带与磁头之间的结构问题,高频区的频率特性劣化。同时,信号中包含的噪声成分在高频区大于低频区,故在强制加重高频成分时S/N比大大劣化。
发明内容
为解决以上问题,本发明的目的在于提供一种装置,用以通过在重放一音频信号过程中加重高频重放信号同时截除高频区噪声,来补偿重放高频信号的频率特性,并改进信噪比。
为实现以上目的,所提供的重放音频信号的频率特性补偿装置包含有:只通过重放信号高频成分的高通滤波器、从高通滤波后的重放信号截除两预定电平之间的信号以产生限幅信号的限幅器以及将限幅信号叠加于重放信号以加重高频号的加法器。
附图说明
本发明的以上目的及其优点经参照附图对一优选实施例作详细说明而变得更加直观。其中:
图1为录音输入与重放输出之间的关系曲线;
图2为录音期间均衡器的频率特性曲线;
图3为本发明的重放音频信号频率特性补偿装置的电路示意图。
具体实施方式
参照图3,本发明的重放音频信号频率补偿装置包含有:将重放信号放大至预定增益值的第一放大器31、只使一经第一放大器放大的信号的高频成分通过的高通滤波器32、对经高通滤波的信号作非线性放大而不改变其相位的第二放大器33、从经第二放大器放大的信号截除某2个电平之间的信号的限幅器34、将第一放大器31输出的信号与限幅器34输出的信号相叠加的加法器36和将叠加信号放大至预定增益值的第三放大器35。
第一放大器31包含有运算放大器A1、电阻器R1与R2和电容器C1,它将重放音频信号电平放至某一增益值,然后输出经放大的重放音频信号。
高通滤波器32包含有电容器C2和电阻器R3,它接收经第一放大器31放大的输出信号,并截除中、低频成分而只通过高频信号,该高频信号用于补偿高频区重放信号的电平以改进频率特性。
第二放大器33包含有运算放大器A2、电阻器R4至R7和电容器C3至C6。它具有非线性放大特性,使高通滤波后的重放信号输入并放大而没有相移。
限幅器34包含有二极管D1与D2、电阻器R8和电容器C7。它接收第二级放大器33的输出信号,截除某二个电平之间的信号,并输出限幅信号。
更具体地说,假定限幅器34中二极管D1阳极上的电压为V1,当作为限幅器34输入端的二极管D1的阴极电压在V1±0.6V之间时,输入限幅器34的信号通不过二极管D1和D2而被截除。如果把电压V1定为0V,限幅器34截除输入信号中-0.6V与0.6V之间的信号成分。这就是说,因为重放信号中包含的大多数噪声存在于其高频区内,并以低于重放信号的电平分布,所以这种高频噪声便被除掉。
这样一来,限幅器34便截除了包含在重放信号中并具有高频成分的低电平噪声,并输出高频重放信号。
限幅器34将重放信号与一参考电平作比较,并且只把超过一定电平的高频重放信号输出给加法器36。这就是说,高频重放信号中的低电平高频噪声成分被截除,经限幅的信号输出给加法器36。
加法器36由电阻器R9和R10组成,它通过相应的电阻器R9和R10将限幅器34的输出信号叠加在第一放大器31的输出信号上。
因此,当只有中频带和低频带频率成分的输入重放信号被高通滤波器32截除时,限幅器34不输出任何录音信号,第一放大器31的输出信号仅是加法器36的输出。
然而,当输出重放信号具有高频成分时,限幅器34只输出其大小超越以预定参数电平为中心的上、下限电平的高频重放信号,以除去重放信号中包括的噪声。然后,把限幅器34的输出信号叠加在放大原始重放信号的第一放大器31的输出信号上,并把叠加的信号加给第三放大器35。
第三放大器35接收加法器36的输出信号,将该信号放大到预定的增益,并输出经放大的信号。
在按上文所述工作的本发明中,当通过均衡器后的重放信号只含有中、低频信号时,并未对重放信号的电平作补偿。而且,当重放信号只包含高频信号时,只对以一参考电平为基准的某一电平以上的高频信号检波,然后将经检波的高频信号叠加于原始重放信号上,从而补偿高频区的频率特性。
如上所述,本发明通过去除重放信号在高频区的噪声成分和控制重放信号电平,改进了重放过程中信号的频率特性,提高了S/N比。
Claims (4)
1.一种重放音频信号频率特性补偿装置,包括:
一高通滤波器,用来只使重放信号的高频成分通过;
一限幅器,它从经所述高通滤波的重放信号中截除两预定电平之间的信号而产生限幅信号;
一加法器,用于将所述限幅信号叠加于重放信号上以加重高频信号。
2.权利要求1的重放音频信号频率特性补偿装置,还包含一非线性放大器用来将所述经高通滤波的重放信号放大到预定增益而在所述高通滤波器和限幅器之间没有相移。
3.权利要求1的重放音频信号频率补偿装置,其中所述限幅器由至少2个二极管组成,并利用二极管的开关特性。
4.权利要求1的重放音频信号频率补偿装置,其中所述限幅器包含:
一第一二极管,其阴极接限幅器输入端,阳极接输出端;
一第二二极管,其阳极接所述输入端,阴极接所述输出端,并与第一二极管相并联;
一电容器和一电阻器,它们把所述输出端与地串联。
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1019960053084A KR100213073B1 (ko) | 1996-11-09 | 1996-11-09 | 재생 오디오 신호의 주파수 특성 보상 장치 |
KR53084/1996 | 1996-11-09 | ||
KR53084/96 | 1996-11-09 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1182270A CN1182270A (zh) | 1998-05-20 |
CN1112761C true CN1112761C (zh) | 2003-06-25 |
Family
ID=19481360
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN97102419A Expired - Fee Related CN1112761C (zh) | 1996-11-09 | 1997-02-03 | 重放音频信号的频率特性补偿装置 |
Country Status (9)
Country | Link |
---|---|
US (1) | US5881157A (zh) |
JP (1) | JP3311958B2 (zh) |
KR (1) | KR100213073B1 (zh) |
CN (1) | CN1112761C (zh) |
BR (1) | BR9701452A (zh) |
DE (1) | DE19704519B4 (zh) |
GB (1) | GB2319444B (zh) |
MY (1) | MY118280A (zh) |
RU (1) | RU2197057C2 (zh) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050259833A1 (en) * | 1993-02-23 | 2005-11-24 | Scarpino Frank A | Frequency responses, apparatus and methods for the harmonic enhancement of audio signals |
JP3644259B2 (ja) * | 1998-03-24 | 2005-04-27 | 株式会社村田製作所 | スピーカ装置 |
US6795740B1 (en) | 2000-03-01 | 2004-09-21 | Apple Computer, Inc. | Rectifying overflow and underflow in equalized audio waveforms |
US7676043B1 (en) * | 2005-02-28 | 2010-03-09 | Texas Instruments Incorporated | Audio bandwidth expansion |
US20090192793A1 (en) * | 2008-01-30 | 2009-07-30 | Desmond Arthur Smith | Method for instantaneous peak level management and speech clarity enhancement |
CA2729678A1 (en) * | 2008-06-30 | 2010-01-07 | Able Planet, Incorporated | Method and system for auditory enhancement and hearing conservation |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4241266A (en) * | 1979-02-05 | 1980-12-23 | Orban Robert A | Peak-limiting apparatus for audio signal |
US5168526A (en) * | 1990-10-29 | 1992-12-01 | Akg Acoustics, Inc. | Distortion-cancellation circuit for audio peak limiting |
CN1100875A (zh) * | 1993-09-16 | 1995-03-29 | 松下电器产业株式会社 | 噪声抑制装置 |
Family Cites Families (8)
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---|---|---|---|---|
US3333055A (en) * | 1963-06-01 | 1967-07-25 | Fernseh Gmbh | Apparatus for increasing the signal-to-noise ratio of a television signal |
NL163388C (nl) * | 1971-05-04 | 1980-08-15 | Philips Nv | Ruisonderdrukkingsschakeling. |
US3846716A (en) * | 1973-07-03 | 1974-11-05 | M Dyatlov | Method of regulating light emitting power of laser and apparatus for effecting same |
US4208548A (en) * | 1977-07-19 | 1980-06-17 | Orban Associates, Inc. | Apparatus and method for peak-limiting audio frequency signals |
JPS5746517A (en) * | 1980-09-03 | 1982-03-17 | Sony Corp | Noise reduction circuit |
DE3837538C2 (de) * | 1988-02-03 | 1996-10-17 | Pioneer Electronic Corp | Lautstärkesteuerschaltung mit Frequenzgangkompensation für ein Audiowiedergabegerät eines Kraftfahrzeugs |
US4894566A (en) * | 1988-10-18 | 1990-01-16 | Rush Michael J | Noise reduction circuit |
US5515446A (en) * | 1992-10-02 | 1996-05-07 | Velmer; George | Electronic audio accurate reproduction system and method |
-
1996
- 1996-11-09 KR KR1019960053084A patent/KR100213073B1/ko not_active IP Right Cessation
-
1997
- 1997-01-31 GB GB9701992A patent/GB2319444B/en not_active Expired - Fee Related
- 1997-02-03 CN CN97102419A patent/CN1112761C/zh not_active Expired - Fee Related
- 1997-02-03 US US08/794,645 patent/US5881157A/en not_active Expired - Fee Related
- 1997-02-04 MY MYPI97000422A patent/MY118280A/en unknown
- 1997-02-06 DE DE19704519A patent/DE19704519B4/de not_active Expired - Fee Related
- 1997-03-24 BR BR9701452A patent/BR9701452A/pt not_active Application Discontinuation
- 1997-03-27 JP JP07536297A patent/JP3311958B2/ja not_active Expired - Fee Related
- 1997-03-28 RU RU97105000/28A patent/RU2197057C2/ru not_active IP Right Cessation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4241266A (en) * | 1979-02-05 | 1980-12-23 | Orban Robert A | Peak-limiting apparatus for audio signal |
US5168526A (en) * | 1990-10-29 | 1992-12-01 | Akg Acoustics, Inc. | Distortion-cancellation circuit for audio peak limiting |
CN1100875A (zh) * | 1993-09-16 | 1995-03-29 | 松下电器产业株式会社 | 噪声抑制装置 |
Also Published As
Publication number | Publication date |
---|---|
GB2319444A (en) | 1998-05-20 |
GB2319444B (en) | 1998-12-16 |
MY118280A (en) | 2004-09-30 |
DE19704519B4 (de) | 2005-10-27 |
BR9701452A (pt) | 1998-09-08 |
RU2197057C2 (ru) | 2003-01-20 |
JPH10164688A (ja) | 1998-06-19 |
CN1182270A (zh) | 1998-05-20 |
KR100213073B1 (ko) | 1999-08-02 |
KR19980034883A (ko) | 1998-08-05 |
DE19704519A1 (de) | 1998-05-14 |
US5881157A (en) | 1999-03-09 |
JP3311958B2 (ja) | 2002-08-05 |
GB9701992D0 (en) | 1997-03-19 |
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