US3919480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decoding apparatus for reproducing four separate information signals
Assignee: Sony Corp
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Filing: 1974-11-22
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Granted: 1975-11-11
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Expires: 1994-11-22
Abstract
Abstract An apparatus for decoding four separate channels of information transduced from a medium having two separate tracks and for presenting the same on four loudspeakers to give a listener the illusion of sound coming from a corresponding number of separate sources. The realism is enhanced by a decoding system which accepts two output signals from the medium, separates them into four independent channels each carrying predominantly the information contained in a respective one of the original signals and, utilizing a logic system, derives control signals for controlling the delay time of delay circuits associated with the four separate channels. The use of the delay circuits improves the separation of the four channels, thereby to enhance the realism of four channel simulation.
Inventors
- 👤 Takeshi Fukami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:08
CPC Classifications
H; H04; H04S; H04S3/00; H04S3/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
161 words
A decoding apparatus for reproducing four separate information signals comprising: A. a decoder for receiving first and second composite signals each of which includes at least three of the four information signals in preselected amplitude and phase relationships and for producing first, second, third and fourth output signals, respectively, containing a different one of said information signals as a predominant signal and a different pair of said audio information signals as subdominant signals; B. first, second, third, and fourth transmitting channels for transmitting said first, second, third and fourth output signals, respectively; C. a control signal producing circuit for producing at least one control signal by comparing the magntidues of said predominant signals in at least two of said transmitting channels; and D. variable delay circuits connected to said transmitting channels, respectively, to transmit respective ones of the output signals and connected to said control signal producing circuit to be controlled by the signal therefrom to delay said output signals selectively.
Claim 2
Dependent Claim
161 words
A decoding apparatus for reproducing four separate information signals comprising: A. a decoder for receiving first and second composite signals each of which includes at least three of the four information signals in preselected amplitude and phase relationships and for producing first, second, third and fourth output signals, respectively, containing a different one of said information signals as a predominant signal and a different pair of said audio information signals as subdominant signals; B. first, second, third, and fourth transmitting channels for transmitting said first, second, third and fourth output signals, respectively; C. a control signal producing circuit for producing at least one control signal by comparing the magntidues of said predominant signals in at least two of said transmitting channels; and D. variable delay circuits connected to said transmitting channels, respectively, to transmit respective ones of the output signals and connected to said control signal producing circuit to be controlled by the signal therefrom to delay said output signals selectively.
Claim 3
Dependent Claim
59 words
A decoding apparatus for reproducing four separate information signals according to claim 1, comprising a variable frequency oscillator connected to said control signal producing circuit to be controlled thereby and connected to said variable delay circuit, said variable delay circuit comprising an element that has delay time determined in reverse proportion to the frequency of said variable frequency oscillator.
Claim 4
Dependent Claim
105 words
A decoding apparatus for reproducing four separate information signals according to claim 2, in which said control signal producing circuit comprises: A. a rectifying circuit for rectifying said fiRst, second, third and fourth output signals; B. a first subtracting circuit for subtracting said second rectified signal from said first rectified signal to produce a first difference signal; C. a second subtracting circuit for subtracting said fourth rectified signal from said first rectified signal to produce a second difference signal; and D. a comparing circuit for comparing the magnitudes of said first and second difference signals for producing first and second control signals with opposite polarities.
Claim 5
Dependent Claim
43 words
A decoding apparatus for reproducing four separate information signals according to claim 1, in which gain control amplifiers are connected to said first, second, third and fourth transmitting channels, respectively, the gain of said variable gain amplifiers being controlled by said control signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |