Patent US4097688A successfully refreshed from Google Patents.
US4097688A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic reproducing system
Assignee: Panasonic Holdings Corp
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Filing: 1971-11-03
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Granted: 1978-06-27
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Expires: 1991-11-03
Abstract
Abstract A stereophonic reproducing system having left signal and right signal channels and impedance provided between the two channels, whereby steady acoustic effects of 4-channel stereo may be simply obtained from 2-channel stereophonic signals.
Inventors
- 👤 Yoshiaki Ochi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:07
CPC Classifications
H; H04; H04S; H04S5/00; H04S5/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
237 words
An audio reproduction system comprising: left and right input terminals for receiving left and right signals respectively, left and right amplifiers having their inputs coupled to said left and right terminals respectively, front-left and rear-left amplifiers coupled to the output of said left amplifier, and front-right and rear-right amplifiers coupled to the output of said right amplifier, front-left and front-right speakers coupled to the outputs of said front-left and front-right amplifiers respectively, rear-left and rear-right speakers coupled in series between the outputs of said rear-left and rear-right amplifiers, a different one of said speakers being positioned approximately at each of the four corners of a quadrilateral area, which may be occupied by a listener, said speakers directing sound towards the interior of the area, wherein said front-left and front-right speakers are respectively positioned in the left and right front corners of the area behind the listener and said rear-left and rear-right speakers are positioned in the left and right rear corners of the area facing the listener, and an impedance element coupling said rear-left and rear-right amplifiers, the impedance of said impedance element having a substantial value capable of supplying partial leakage of a signal amplified by said rear-left amplifier to said rear-right amplifier and partial leakage of a signal amplified by said rear-right amplifier to said rear-left amplifier without degradation of the degree of separation between sound signals supplied to said front-left and front-right speakers, respectively.
Claim 2
Dependent Claim
237 words
An audio reproduction system comprising: left and right input terminals for receiving left and right signals respectively, left and right amplifiers having their inputs coupled to said left and right terminals respectively, front-left and rear-left amplifiers coupled to the output of said left amplifier, and front-right and rear-right amplifiers coupled to the output of said right amplifier, front-left and front-right speakers coupled to the outputs of said front-left and front-right amplifiers respectively, rear-left and rear-right speakers coupled in series between the outputs of said rear-left and rear-right amplifiers, a different one of said speakers being positioned approximately at each of the four corners of a quadrilateral area, which may be occupied by a listener, said speakers directing sound towards the interior of the area, wherein said front-left and front-right speakers are respectively positioned in the left and right front corners of the area behind the listener and said rear-left and rear-right speakers are positioned in the left and right rear corners of the area facing the listener, and an impedance element coupling said rear-left and rear-right amplifiers, the impedance of said impedance element having a substantial value capable of supplying partial leakage of a signal amplified by said rear-left amplifier to said rear-right amplifier and partial leakage of a signal amplified by said rear-right amplifier to said rear-left amplifier without degradation of the degree of separation between sound signals supplied to said front-left and front-right speakers, respectively.
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) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |