JPS5740712A - Audio signal reproducing device equipped with noise eliminating circuit - Google Patents
Audio signal reproducing device equipped with noise eliminating circuitInfo
- Publication number
- JPS5740712A JPS5740712A JP55115962A JP11596280A JPS5740712A JP S5740712 A JPS5740712 A JP S5740712A JP 55115962 A JP55115962 A JP 55115962A JP 11596280 A JP11596280 A JP 11596280A JP S5740712 A JPS5740712 A JP S5740712A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- previous
- signal
- period
- transient
- 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.)
- Pending
Links
Classifications
-
- 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
- G11B20/24—Signal processing not specific to the method of recording or reproducing; Circuits therefor for reducing noise
Abstract
PURPOSE:To reduce noises by shortening a previous-value holding time when the previous value of the output signal of an LPF is held, by changing an input to a previous-value holding circuit over to a signal, which neither passes through the LPF nor has a transient period, during the transient periood of the LPF. CONSTITUTION:An audio FM signal passed through a BPF2 is detected by a dropout detecting circuit 7 and the trailing edge of its dropout detection signal is used as a trigger to operate a monostable multivibrator 16, so that a pulse having pulse width equivalent to the short transient period of a signal delay circuit 14 is outputted. Then, an OR circuit 9 is operated to operate a previous-value holding circuit, and the trailing edge of the output signal of an OR circuit 12 is used as a trigger to operate a monostable multivibrator 18, thereby generating and outputting a pulse reading the trailing edge of the long transient period of an LPF5 to an OR circuit 19. Consequently, the input side of the circuit 6 is changed over to the side of a signal delay circuit 14 in the very short transient period of the BPF2 only during the period when the transient phenomenon of the LPF5 attenuates, so the previous- value holding period is shortened to reduce noises due to dropouts.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55115962A JPS5740712A (en) | 1980-08-25 | 1980-08-25 | Audio signal reproducing device equipped with noise eliminating circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP55115962A JPS5740712A (en) | 1980-08-25 | 1980-08-25 | Audio signal reproducing device equipped with noise eliminating circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5740712A true JPS5740712A (en) | 1982-03-06 |
Family
ID=14675437
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP55115962A Pending JPS5740712A (en) | 1980-08-25 | 1980-08-25 | Audio signal reproducing device equipped with noise eliminating circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5740712A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS59142710A (en) * | 1983-02-04 | 1984-08-16 | Hitachi Ltd | Eliminating circuit for noise of frequency-modulated sound signal |
US4988859A (en) * | 1988-05-13 | 1991-01-29 | Hamamatsu Photonics Kabushiki Kaisha | Optical waveform measuring device |
US5043568A (en) * | 1989-04-11 | 1991-08-27 | Hamamatsu Photonics K. K. | Optical signal detector incorporating means for eluminating background light |
-
1980
- 1980-08-25 JP JP55115962A patent/JPS5740712A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS59142710A (en) * | 1983-02-04 | 1984-08-16 | Hitachi Ltd | Eliminating circuit for noise of frequency-modulated sound signal |
US4988859A (en) * | 1988-05-13 | 1991-01-29 | Hamamatsu Photonics Kabushiki Kaisha | Optical waveform measuring device |
US5043568A (en) * | 1989-04-11 | 1991-08-27 | Hamamatsu Photonics K. K. | Optical signal detector incorporating means for eluminating background light |
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