GB1404333A - Selectively switchable signal compressor/expander - Google Patents
Selectively switchable signal compressor/expanderInfo
- Publication number
- GB1404333A GB1404333A GB3364572A GB3364572A GB1404333A GB 1404333 A GB1404333 A GB 1404333A GB 3364572 A GB3364572 A GB 3364572A GB 3364572 A GB3364572 A GB 3364572A GB 1404333 A GB1404333 A GB 1404333A
- Authority
- GB
- United Kingdom
- Prior art keywords
- expander
- input
- further path
- compressor
- terminal
- 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)
- Television Signal Processing For Recording (AREA)
- Signal Processing For Digital Recording And Reproducing (AREA)
Abstract
1404333 Companders DOLBY LABORATORIES Inc 18 July 1972 [2 Aug 1971] 33645/72 Heading H4R A selectively switchable compressor expander has a combining circuit 51A in a main path extending between an input terminal C and a second terminal 53 with a further path 26 supplying a second input to the combining circuit and including signal limiting means, preferably of the type described in Specification 1,279,634 using filters whose cutoff varies with frequency, which renders the input to the combining means from the further path only effective at low signal levels. A switch 24 is arranged in one position to connect the further path in a feedback loop from the output of the combining circuit to the second input thereto to form a compressor. In addition a second combining circuit 51B is connected across the further path, 26, in at least one setting of the switch, to combine the signals at the input and output of the further path to provide an expanded monitor signal at a first output terminal 25, while the other position of switch 24 forms the circuit into an expander feeding terminal 53. The arrangement shown in Fig. 2 provides a feedback compressor between the input and terminal 35 or 35A in the record position of switch 24 while the compressed signal is expanded in a feedforward expander, formed by combiner 51B, further path 26 and inverter 52B, to provide a monitor signal at terminal 25. A similar arrangement is provided by the circuit of Fig. 3 (not shown), with the feedback compressor and feedforward expander provided by different combining networks (51A and 51B) with switching to render one or other effective, and a further combining circuit (51C) connected permanently across the further path to provide an expanded monitor signal. The circuit of Fig. 2 provides a feedforward compressor, using combiner 51B and further path 26 or a feedback expander, using combiner 51A, further path 26, and inverter 52. A monitor point 25 is provided connected to the output of the expander and to the input of the compressor.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16806971A | 1971-08-02 | 1971-08-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1404333A true GB1404333A (en) | 1975-08-28 |
Family
ID=22609984
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3364472A Expired GB1404332A (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 |
GB3364672A Expired GB1404334A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
GB3364572A Expired GB1404333A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
Family Applications Before (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3364472A Expired GB1404332A (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 |
GB3364672A Expired GB1404334A (en) | 1971-08-02 | 1972-07-18 | Selectively switchable signal compressor/expander |
Country Status (4)
Country | Link |
---|---|
US (1) | US3729693A (en) |
JP (4) | JPS5625824B2 (en) |
DE (4) | DE2237543B2 (en) |
GB (4) | GB1404332A (en) |
Families Citing this family (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3903485A (en) * | 1968-01-10 | 1975-09-02 | Ray Milton Dolby | Compressors, expanders and noise reduction systems |
US3972010A (en) * | 1968-01-10 | 1976-07-27 | 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 |
US4328465A (en) * | 1978-09-26 | 1982-05-04 | Pioneer Electronic Corporation | Tone control circuit utilizing variable gain amplifier |
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 |
AU7585581A (en) * | 1981-08-26 | 1983-03-08 | Bloy, Graham Philip | 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 |
US4741039A (en) * | 1982-01-26 | 1988-04-26 | Metme Corporation | System for maximum efficient transfer 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 | ||
EP0356885A3 (en) * | 1988-08-23 | 1991-05-15 | B.W.N. Wavepur Rights Company | Frequency-compensated linear sliding band network |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH447890A (en) * | 1965-07-09 | 1967-11-30 | Dowty Electrics Ltd | Electrically controlled indicator |
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 GB3364472A patent/GB1404332A/en not_active Expired
- 1972-07-18 GB GB3362472A patent/GB1404331A/en not_active Expired
- 1972-07-18 GB GB3364672A patent/GB1404334A/en not_active Expired
- 1972-07-18 GB GB3364572A patent/GB1404333A/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
- 1972-07-31 DE DE2237542A patent/DE2237542C2/en not_active Expired
- 1972-07-31 DE DE2237540A patent/DE2237540C2/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 |
---|---|
DE2237542A1 (en) | 1973-02-22 |
DE2237540C2 (en) | 1982-07-15 |
JPS5625824B2 (en) | 1981-06-15 |
GB1404334A (en) | 1975-08-28 |
JPS4825426A (en) | 1973-04-03 |
JPS4825424A (en) | 1973-04-03 |
JPS53888B2 (en) | 1978-01-12 |
DE2237540A1 (en) | 1973-02-22 |
JPS4825425A (en) | 1973-04-03 |
JPS5737134B2 (en) | 1982-08-07 |
DE2237543B2 (en) | 1977-12-08 |
DE2237543A1 (en) | 1973-02-22 |
DE2237541C2 (en) | 1982-08-05 |
GB1404331A (en) | 1975-08-28 |
JPS5737135B2 (en) | 1982-08-07 |
US3729693A (en) | 1973-04-24 |
DE2237542C2 (en) | 1982-04-29 |
GB1404332A (en) | 1975-08-28 |
DE2237541A1 (en) | 1973-02-22 |
JPS4825427A (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 |