US4748501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cable converter for television signals with stereo audio signal
Assignee: Zenith Electronics LLC
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Filing: 1984-12-11
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Granted: 1988-05-31
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Expires: 2004-12-11
Abstract
Abstract A cable converter for a television signal transmission having a stereo audio signal includes a coaxial output jack supplied with a 4.5 MHz aural intercarrier and a DC voltage for volume control and mute purposes. An interface circuit includes a pair of transistors connected in series for controlling the DC voltage level on the output jack as a function of desired volume level. One of the two transistors functions as a switch that may be operated from the cable head-end to provide a mute voltage level at the output jack for disabling the audio for nonauthorized channels. Optionally, a head-end control signal may operate another transistor for preventing coupling of the 4.5 Mhz aural intercarrier to the output jack.
Inventors
- 👤 Michael E. Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:06
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/10; H04N7/102; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/20; H04R; H04R3/00; H04R3/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A converter, including an input terminal, a video output terminal and an audio output terminal, for translating received television signal transmissions including a video signal and a stereo audio signal comprising: means for receiving said television signal transmissions at said input terminal and for developing therefrom said video signal and a 4.5 MHz aural intercarrier containing said stereo audio signal; means supplying said video signal to said video output terminal; means for developing a variable DC audio level signal for enabling control of the volume level of said stereo audio signal in an uninterrupted continuously variable manner; and interface means for combining said 4.5 MHz aural intercarrier with said variable DC audio level signal and for applying them to said audio output terminal.
Claim 2
Dependent Claim
123 words
A converter, including an input terminal, a video output terminal and an audio output terminal, for translating received television signal transmissions including a video signal and a stereo audio signal comprising: means for receiving said television signal transmissions at said input terminal and for developing therefrom said video signal and a 4.5 MHz aural intercarrier containing said stereo audio signal; means supplying said video signal to said video output terminal; means for developing a variable DC audio level signal for enabling control of the volume level of said stereo audio signal in an uninterrupted continuously variable manner; and interface means for combining said 4.5 MHz aural intercarrier with said variable DC audio level signal and for applying them to said audio output terminal.
Claim 3
Dependent Claim
29 words
The converter of claim 1 wherein said variable DC audio level signal is adjustable to a mute level for muting said stereo audio signal in said television signal transmission.
Claim 4
Dependent Claim
57 words
The converter of claim 2 wherein said interface means include: an authorized signal terminal and a volume signal terminal; a volume control transistor coupled to said volume signal terminal; and a switch transistor connected in the load circuit of said volume control transistor and coupled to said authorized signal terminal for cutting off said volume control transistor.
Claim 5
Dependent Claim
112 words
A converter for translating a television signal transmission having a video signal and a stereo audio signal comprising: means for receiving said television signal transmission and for developing therefrom said video signal and a 4.5 MHz aural intercarrier containing said stereo audio signal; means for developing a variable DC audio level signal that is continuously variable in an uninterrupted manner from a remote point, said variable DC audio level signal having a mute level for muting said stereo audio signal in said television signal transmission; and transistor interface means for combining said 4.5 MHz aural intercarrier and said variable DC audio level signal and for applying them to a common output jack.
Claim 6
Dependent Claim
112 words
A converter for translating a television signal transmission having a video signal and a stereo audio signal comprising: means for receiving said television signal transmission and for developing therefrom said video signal and a 4.5 MHz aural intercarrier containing said stereo audio signal; means for developing a variable DC audio level signal that is continuously variable in an uninterrupted manner from a remote point, said variable DC audio level signal having a mute level for muting said stereo audio signal in said television signal transmission; and transistor interface means for combining said 4.5 MHz aural intercarrier and said variable DC audio level signal and for applying them to a common output jack.
Claim 7
Dependent Claim
191 words
A converter for receiving a television signal transmission including a video signal and a stereo audio signal and means for supplying said video signal to a terminal and for supplying a stereo audio signal adapter including a multi-pin jack having certain pins for receiving, respectively, a 4.5 MHz aural intercarrier, a DC volume control signal and a mute signal comprising: means for developing a 4.5 MHz aural intercarrier including said stereo audio signal from said received television signal transmission; means for developing a variable DC volume control signal that is continuously variable in an uninterrupted manner and that includes a level corresponding to said mute signal for controlling the muting and the level of said stereo audio signal in said television signal transmission; interface means for combining said 4.5 MHz aural intercarrier and said variable DC volume control signal and for applying them to a single coaxial output jack; a cable interconnect having a coaxial plug at one end for connection to said coaxial output jack and a mating multi-pin plug at the other end for connection to said multi-pin jack; and means interconnecting said cetain pins of said multi-pin plug.
Claim 8
Dependent Claim
191 words
A converter for receiving a television signal transmission including a video signal and a stereo audio signal and means for supplying said video signal to a terminal and for supplying a stereo audio signal adapter including a multi-pin jack having certain pins for receiving, respectively, a 4.5 MHz aural intercarrier, a DC volume control signal and a mute signal comprising: means for developing a 4.5 MHz aural intercarrier including said stereo audio signal from said received television signal transmission; means for developing a variable DC volume control signal that is continuously variable in an uninterrupted manner and that includes a level corresponding to said mute signal for controlling the muting and the level of said stereo audio signal in said television signal transmission; interface means for combining said 4.5 MHz aural intercarrier and said variable DC volume control signal and for applying them to a single coaxial output jack; a cable interconnect having a coaxial plug at one end for connection to said coaxial output jack and a mating multi-pin plug at the other end for connection to said multi-pin jack; and means interconnecting said cetain pins of said multi-pin plug.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |