GB1404332A - Selectively switchable signal compressor/expander - Google Patents
Selectively switchable signal compressor/expanderInfo
- Publication number
- GB1404332A GB1404332A GB3364472A GB3364472A GB1404332A GB 1404332 A GB1404332 A GB 1404332A GB 3364472 A GB3364472 A GB 3364472A GB 3364472 A GB3364472 A GB 3364472A GB 1404332 A GB1404332 A GB 1404332A
- Authority
- GB
- United Kingdom
- Prior art keywords
- configuration
- expander
- compressor
- adder
- input
- 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
Links
Classifications
-
- 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
- H03G9/02—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers
- H03G9/025—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers frequency-dependent volume compression or expansion, e.g. multiple-band systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/62—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
- H04B1/64—Volume compression or expansion arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
- Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Signal Processing For Digital Recording And Reproducing (AREA)
- Television Signal Processing For Recording (AREA)
Abstract
1404332 Companders DOLBY LABORATORIES Inc 18 July 1972 [2 Aug 1971] 33644/72 Heading H4R A selectively switchable compressor and expander comprises two adding circuits 51A and 51B for connection in a main path between an input and an output terminal and a further path 26 whose input is connected to the input of one of the adders 51B and connectible via a switch 24 with either the output of the other adder, 51A, or an input terminal. The output of the further path 26 is connected direct to the second inputs of one of the adding circuits to form a compressor configuration, and via an inverter 52 to the second input of the other adding circuit to form an expander configuration, the compressor configuration being selected by positioning of switch 24 in the record position R and the expander configuration with switch 24 in playback position P. The further path includes signal limiting means so that it is only effective on low signal levels and preferably includes filters whose cutoff varies with signal level as described in Specification 1,279,634. Fig. 5 shows an arrangement in which the compressor operates, using adder 51B in a feed forward configuration and the expander, using adder 51A in a feedback configuration, while in Fig. 6, the compressor, using adder 51A, operates in feedback configuration and the expander, using adder 51B, in feedforward configuration. Switch 55 renders the circuit inoperative.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16806971A | 1971-08-02 | 1971-08-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1404332A true GB1404332A (en) | 1975-08-28 |
Family
ID=22609984
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3364572A Expired GB1404333A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
GB3364672A Expired GB1404334A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
GB3362472A Expired GB1404331A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable compressor/expanders |
GB3364472A Expired GB1404332A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
Family Applications Before (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3364572A Expired GB1404333A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
GB3364672A Expired GB1404334A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
GB3362472A Expired GB1404331A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable compressor/expanders |
Country Status (4)
Country | Link |
---|---|
US (1) | US3729693A (en) |
JP (4) | JPS5625824B2 (en) |
DE (4) | DE2237542C2 (en) |
GB (4) | GB1404333A (en) |
Families Citing this family (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3972010A (en) * | 1968-01-10 | 1976-07-27 | Ray Milton Dolby | Compressors, expanders and noise reduction systems |
US3903485A (en) * | 1968-01-10 | 1975-09-02 | Ray Milton Dolby | Compressors, expanders and noise reduction systems |
GB1432763A (en) * | 1972-05-02 | 1976-04-22 | Dolby Laboratories Inc | Compressors expanders and noise reduction systems |
JPS572970B2 (en) * | 1973-09-10 | 1982-01-19 | ||
US4045731A (en) * | 1974-11-21 | 1977-08-30 | Takeda Riken Kogyo Kabushikikaisha | Filter having an automatically controlled variable cut-off frequency |
JPS51118718U (en) * | 1975-03-19 | 1976-09-27 | ||
US4155041A (en) | 1976-05-13 | 1979-05-15 | Burns Richard C | System for reducing noise transients |
GB1579138A (en) * | 1976-07-06 | 1980-11-12 | Sony Corp | Noise and cross-talk elimination in recording and reproducing video signals |
JPS5313860A (en) * | 1976-07-23 | 1978-02-07 | Pioneer Electronic Corp | Tone control device |
US4068139A (en) * | 1976-08-09 | 1978-01-10 | Fairchild Camera And Instrument Corporation | IC compatible variable shunt impedance for Dolby B system |
JPS5329007A (en) * | 1976-08-30 | 1978-03-17 | Victor Co Of Japan Ltd | Signal transmitter |
JPS5373020A (en) * | 1976-12-13 | 1978-06-29 | Victor Co Of Japan Ltd | Signal transmission device |
JPS53121506A (en) * | 1977-03-31 | 1978-10-24 | Pioneer Electronic Corp | Signal compressing and expanding device |
JPS5439516A (en) * | 1977-09-02 | 1979-03-27 | Sanyo Electric Co Ltd | Noise reduction unit |
GB2034138B (en) * | 1978-09-26 | 1983-03-23 | Pioneer Electronic Corp | Variable gain amplifier circuit |
JPS55121698U (en) * | 1979-02-21 | 1980-08-29 | ||
JPS55156431A (en) * | 1979-05-24 | 1980-12-05 | Sony Corp | Noise reduction system |
JPS55158715A (en) * | 1979-05-29 | 1980-12-10 | Sony Corp | Gain control circuit |
DE3102945A1 (en) * | 1980-05-19 | 1981-12-24 | Hitachi, Ltd., Tokyo | SWITCHABLE SIGNAL COMPRESSOR / SIGNAL EXTENDER |
US4457014A (en) * | 1980-10-03 | 1984-06-26 | Metme Communications | Signal transfer and system utilizing transmission lines |
JPS57142013A (en) * | 1981-02-27 | 1982-09-02 | Sony Corp | Active equalizer |
EP0086777A1 (en) * | 1981-08-26 | 1983-08-31 | EBERHARDT, Alfred F. | System for maximum efficiency transfer of modulated signals utilizing line systems |
JPS57117111A (en) * | 1981-11-20 | 1982-07-21 | Matsushita Electric Ind Co Ltd | Tape recorder |
DE3249333T (en) * | 1982-01-26 | 1984-01-12 | Coghill, Marvin, Bangkok | System for maximum effective transmission of modulated energy |
JPS58209234A (en) * | 1982-05-29 | 1983-12-06 | Sony Corp | Noise reduction circuit |
JPS5933113U (en) * | 1982-08-23 | 1984-03-01 | 株式会社東芝 | Tape recorder switching device |
JPS5995414U (en) * | 1982-12-17 | 1984-06-28 | 株式会社日立製作所 | Tape recorder with noise reduction circuit |
JPS6062639U (en) * | 1983-10-05 | 1985-05-01 | カヤバ工業株式会社 | Hydraulic shock absorber mounting device |
US4747141A (en) * | 1983-10-24 | 1988-05-24 | Kahn Leonard R | AM stereo signal decoder |
JPH0725854B2 (en) * | 1984-05-18 | 1995-03-22 | 帝国化学産業株式会社 | Water-solubilization method of polyamide resin |
DE3543907A1 (en) * | 1985-12-12 | 1987-06-25 | Stefan Knauer | Device for noise suppression in the transmission of audio-frequency signals |
JPH0244113Y2 (en) * | 1987-03-26 | 1990-11-22 | ||
JPS6421833U (en) * | 1987-07-29 | 1989-02-03 | ||
WO1990002446A1 (en) * | 1988-08-23 | 1990-03-08 | B.W.N. Wavepur Rights Company | Frequency-compensated linear sliding-band network |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1487274A1 (en) * | 1965-07-09 | 1969-04-03 | Dowty Electrics Ltd | Electric display instrument |
GB1120541A (en) * | 1965-08-11 | 1968-07-17 | Dolby Ray Milton | Improvements in noise reduction systems |
GB1253031A (en) * | 1968-01-10 | 1971-11-10 | ||
US3631365A (en) * | 1968-11-01 | 1971-12-28 | Dolby Laboratories Inc | Signal compressors and expanders |
-
1971
- 1971-08-02 US US00168069A patent/US3729693A/en not_active Expired - Lifetime
-
1972
- 1972-07-18 GB GB3364572A patent/GB1404333A/en not_active Expired
- 1972-07-18 GB GB3364672A patent/GB1404334A/en not_active Expired
- 1972-07-18 GB GB3362472A patent/GB1404331A/en not_active Expired
- 1972-07-18 GB GB3364472A patent/GB1404332A/en not_active Expired
- 1972-07-31 DE DE2237542A patent/DE2237542C2/en not_active Expired
- 1972-07-31 DE DE2237540A patent/DE2237540C2/en not_active Expired
- 1972-07-31 DE DE19722237543 patent/DE2237543B2/en not_active Ceased
- 1972-07-31 DE DE2237541A patent/DE2237541C2/en not_active Expired
- 1972-08-02 JP JP7698572A patent/JPS5625824B2/ja not_active Expired
- 1972-08-02 JP JP7698772A patent/JPS5737135B2/ja not_active Expired
- 1972-08-02 JP JP7698872A patent/JPS53888B2/ja not_active Expired
- 1972-08-02 JP JP7698672A patent/JPS5737134B2/ja not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS4825426A (en) | 1973-04-03 |
JPS4825424A (en) | 1973-04-03 |
DE2237540A1 (en) | 1973-02-22 |
JPS5625824B2 (en) | 1981-06-15 |
DE2237541C2 (en) | 1982-08-05 |
GB1404334A (en) | 1975-08-28 |
DE2237543A1 (en) | 1973-02-22 |
DE2237543B2 (en) | 1977-12-08 |
DE2237542C2 (en) | 1982-04-29 |
GB1404333A (en) | 1975-08-28 |
DE2237540C2 (en) | 1982-07-15 |
US3729693A (en) | 1973-04-24 |
JPS53888B2 (en) | 1978-01-12 |
JPS4825427A (en) | 1973-04-03 |
DE2237542A1 (en) | 1973-02-22 |
JPS5737134B2 (en) | 1982-08-07 |
GB1404331A (en) | 1975-08-28 |
JPS5737135B2 (en) | 1982-08-07 |
DE2237541A1 (en) | 1973-02-22 |
JPS4825425A (en) | 1973-04-03 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PE20 | Patent expired after termination of 20 years |