US3849600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic signal reproducing apparatus
Assignee: Sony Corp
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Filing: 1973-10-11
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Granted: 1974-11-19
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Expires: 1993-10-11
Abstract
Abstract In a stereophonic signal reproducing apparatus, there are provided left and right loudspeaker systems for reproducing sounds in response to oppositely phased difference signals (L-R) and (R-L) that are supplied thereto, a central loudspeaker system disposed between the left and right loudspeaker systems for reproducing sounds in response to a sum signal (L+R) supplied thereto, and a frequency characteristic compensating circuit operable upon the oppositely phased difference signals to vary the frequency response of a signal reproduced from the difference signals such that the reproduced signal strength is relatively high in a low frequency band but relatively low in a high frequency band as compared to the frequency dependent signal strength of the sum signal (L+R). The stereophonic signal reproducing apparatus further has an auxiliary output terminal to which a sound reproducing device of the headphone-type is connected and means for terminating the variation in the frequency response of the reproduced signal by the frequency characteristic compensating circuit when the headphone is connected to the auxiliary output terminal.
Inventors
- 👤 S Ohshima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:15
CPC Classifications
H; H04; H04S; H04S3/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
222 words
A stereophonic signal reproducing apparatus comprising: a. left and right speaker systems and a central speaker system; b. means for applying a difference signal (L-R) proportional to the difference between left and right signals L and R and an oppositely phased difference signal (R-L) to said left and right speaker systems and for applying a Sum signal (L+R) to said central speaker system to thereby produce sounds from said left, right and central speaker systems, the produced sounds being mixed acoustically in space in a matrix manner; c. frequency characteristic compensating means for varying the reproduction frequency response of said difference signals (LR) and (R-L) such that the level of said difference signals is relatively high in a low frequency band but relatively small in a high frequency band as compared with the level of said sum signal (L+R); d. a matrix circuit coupled to said means for applying for mixing said difference signals (L-R), (R-L) and said sum signal (L+R) in a matrix manner to produce left and right signals L and R, respectively; e. auxiliary output terminal means coupled to said matrix circuit and adapted to be supplied with said left and right signals L and R; and f. means operably coupled to said auxiliary output terminal for terminating the variation in the reproduction frequency response of said difference signals.
Claim 2
Dependent Claim
222 words
A stereophonic signal reproducing apparatus comprising: a. left and right speaker systems and a central speaker system; b. means for applying a difference signal (L-R) proportional to the difference between left and right signals L and R and an oppositely phased difference signal (R-L) to said left and right speaker systems and for applying a Sum signal (L+R) to said central speaker system to thereby produce sounds from said left, right and central speaker systems, the produced sounds being mixed acoustically in space in a matrix manner; c. frequency characteristic compensating means for varying the reproduction frequency response of said difference signals (LR) and (R-L) such that the level of said difference signals is relatively high in a low frequency band but relatively small in a high frequency band as compared with the level of said sum signal (L+R); d. a matrix circuit coupled to said means for applying for mixing said difference signals (L-R), (R-L) and said sum signal (L+R) in a matrix manner to produce left and right signals L and R, respectively; e. auxiliary output terminal means coupled to said matrix circuit and adapted to be supplied with said left and right signals L and R; and f. means operably coupled to said auxiliary output terminal for terminating the variation in the reproduction frequency response of said difference signals.
Claim 3
Dependent Claim
48 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said auxiliary output terminal means includes a jack and a switch operable in response to the insertion of connecting means into said jack; and wherein said means for terminating is activated by the operation of said switch.
Claim 4
Dependent Claim
40 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said means for terminating comprises a reverse compensating circuit for cancelling the variation in the reproduction frequency response of said difference signals produced by the frequency characteristic compensating means.
Claim 5
Dependent Claim
34 words
A stereophonic signal reproducing apparatus as claimed in claim 3 wherein said reverse compensating circuit comprises a series connection of two capacitors and a resistor connected in parallel to one of said two capacitors.
Claim 6
Dependent Claim
20 words
A stereophonic signal reproducing apparatus as claimed in claim 3 wherein said reverse compensating circuit is formed of a capacitor.
Claim 7
Dependent Claim
25 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said means for terminating is operable to disconnect said frequency characteristic compensating circuit means.
Claim 8
Dependent Claim
33 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said matrix circuit and said means for terminating are rendered operable when an output is derived from said auxiliary output terminal means.
Claim 9
Dependent Claim
44 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said matrix circuit means and said means for terminating are rendered operable and said speaker systems are disconnected, all at the sametime, when an output is derived from said auxiliary output terminal means.
Claim 10
Dependent Claim
41 words
A stereophonic signal reproducing apparatus as claimed in claim 1 wherein said means for applying a difference signal and an oppositely phased difference signal includes an amplifier and said frequency characteristic compensating means is coupled to the output of said amplifier.
Claim 11
Dependent Claim
52 words
A stereophonic signal reproducing apparatus as claimed in claim 9 wherein said auxiliary output terminal means includes a jack adapted to receive a plug connected to headphone means and further including switch means operable between first and second sets of contacts in response to the reception of said plug by said jack.
Claim 12
Dependent Claim
84 words
A stereophonic signal reproducing apparatus as claimed in claim 10 wherein said means for applying a sum signal includes a further amplifier and wherein said left and right speaker systems are coupled to said amplifier and said central speaker system is coupled to said further amplifier by said first set of contacts of said switch means such that said respective speaker systems are disconnected from said respective amplifiers when said switch means operates in response to the reception of a plug by said jack.
Claim 13
Dependent Claim
73 words
A stereophonic signal reproducing apparatus as claimed in claim 11 wherein said means for terminating comprises a reverse compensatIng circuit connected to one of said second sets of contacts for being operably coupled to said amplifier when said switch means operates in response to the reception of a plug by said jack, to thereby cancel the variation in the reproduction frequency response of said difference signals produced by said frequency characteristic compensating means.
Claim 14
Dependent Claim
47 words
A stereophonic signal reproducing apparatus as claimed in claim 11 wherein said means for terminating comprises a normally closed switch for coupling said frequency characteristic compensating means to said amplifier, said normally closed switch being opened in response to the reception of a plug by said jack.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |