US5204767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pay-channel transmission system for CATV
Assignee: Panasonic Holdings Corp
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Filing: 1991-10-07
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Granted: 1993-04-20
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Expires: 2011-10-07
Abstract
Abstract A pay-channel transmission system for a CATV has an optical transmission unit and an optical receiver unit. The optical transmission unit includes pay-channel television signals optically multiplexed by a λ 1 wavelength semiconductor laser and non-pay-channel television signals optically multiplexed by a λ 2 wavelength semiconductor laser. The optical receiver unit includes an optical filter for filtering the λ 1 wavelength data. Thus, a non-subscriber having the optical filter is prevented from receiving the pay-channel television signals, and a subscriber having no optical filter is able to receive both the pay-channel television signals and non-pay-channel television signals.
Inventors
- 👤 Hiroaki Nakata
- 👤 Kuniaki Utsumi
- 👤 Kazuki Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:41
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/60; H04B10/66; H04B10/69; H04B10/67; H04B10/671; H04B10/675; H04J; H04J14/00; H04J14/02; H04J14/0226; H04J14/0227; H04J14/0228; H04J14/023; H04J14/0232; H04J14/0234; H04J14/0298; H04N; H04N7/00; H04N7/16; H04N7/22; H04J14/0278; H04J14/0282
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
178 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating a frequency multiplexed pay-channel television signal which is multiplexed to an f 1 -f k frequency band and outputs a first optical signal by means of a λ 1 wavelength semiconductor laser; a second optical signal generator for generating a frequency multiplexed non-pay-channel television signal which is multiplexed to a frequency band other than f 1 -f k and outputs a second optical signal by means of a λ 2 wavelength semiconductor laser; and an optical combining means for combining said first and second optical signals; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said first optical signal and for transmitting only said second optical signal, whereby a non-subscriber having said optical blocking means is prevented from receiving the first optical signal, and a subscriber having no optical blocking means is able to receive both the first and second optical signals.
Claim 2
Dependent Claim
178 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating a frequency multiplexed pay-channel television signal which is multiplexed to an f 1 -f k frequency band and outputs a first optical signal by means of a λ 1 wavelength semiconductor laser; a second optical signal generator for generating a frequency multiplexed non-pay-channel television signal which is multiplexed to a frequency band other than f 1 -f k and outputs a second optical signal by means of a λ 2 wavelength semiconductor laser; and an optical combining means for combining said first and second optical signals; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said first optical signal and for transmitting only said second optical signal, whereby a non-subscriber having said optical blocking means is prevented from receiving the first optical signal, and a subscriber having no optical blocking means is able to receive both the first and second optical signals.
Claim 3
Dependent Claim
222 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating a frequency multiplexed pay-channel television signal which is multiplexed to a first frequency band and outputs a first optical signal at a first frequency range by a first semiconductor laser; a second optical signal generator for generating a frequency multiplexed non-pay-channel television signal which is multiplexed to a second frequency band and outputs a second optical signal at a second frequency range by a second semiconductor laser; and an optical combining means for combining said first and second optical signals; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical divider means for separating said first and second optical signals; and first converting means sensitive to said first frequency range for converting said first optical signal to a first electric signal; second converting means sensitive to said second frequency range for converting said second optical signal to a second electric signal; whereby a non-subscriber having no optical divider means and first converting means is prevented from receiving the first electric signal, and a subscriber having said optical divider means and first converting means, as well as the second converting means, is able to receive both the first and second electric signal.
Claim 4
Dependent Claim
222 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating a frequency multiplexed pay-channel television signal which is multiplexed to a first frequency band and outputs a first optical signal at a first frequency range by a first semiconductor laser; a second optical signal generator for generating a frequency multiplexed non-pay-channel television signal which is multiplexed to a second frequency band and outputs a second optical signal at a second frequency range by a second semiconductor laser; and an optical combining means for combining said first and second optical signals; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical divider means for separating said first and second optical signals; and first converting means sensitive to said first frequency range for converting said first optical signal to a first electric signal; second converting means sensitive to said second frequency range for converting said second optical signal to a second electric signal; whereby a non-subscriber having no optical divider means and first converting means is prevented from receiving the first electric signal, and a subscriber having said optical divider means and first converting means, as well as the second converting means, is able to receive both the first and second electric signal.
Claim 5
Dependent Claim
192 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal and non-pay-channel television signal which are separatably added to each other; a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal having a characteristic to interfere with said pay-television signal; an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
Claim 6
Dependent Claim
192 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal and non-pay-channel television signal which are separatably added to each other; a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal having a characteristic to interfere with said pay-television signal; an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
Claim 7
Dependent Claim
214 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal which is frequency multiplexed to an f 1 -f k frequency band and non-pay-channel television signal which is frequency multiplexed to a frequency band other than f 1 -f k , a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal being frequency multiplexed to the f 1 -k k frequency band, an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
Claim 8
Dependent Claim
214 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal which is frequency multiplexed to an f 1 -f k frequency band and non-pay-channel television signal which is frequency multiplexed to a frequency band other than f 1 -f k , a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal being frequency multiplexed to the f 1 -k k frequency band, an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
Claim 9
Dependent Claim
202 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal and non-pay-channel television signal both of which are modulated by a predetermined modulation system; a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal being an inverse of said pay-channel television signal which is modulated by said predetermined modulation system; an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
Claim 10
Dependent Claim
202 words
A pay-channel transmission system for a CATV comprising: (I) an optical transmission unit comprising: a first optical signal generator for generating an optically modulated television signal modulated by a λ 1 wavelength semiconductor, said television signal being a combination of pay-channel television signal and non-pay-channel television signal both of which are modulated by a predetermined modulation system; a second optical signal generator for generating an optically modulated interference signal modulated by a λ 2 wavelength semiconductor, said interference signal being an inverse of said pay-channel television signal which is modulated by said predetermined modulation system; an optical combining means for combining said optically modulated television signal and said optically modulated interference signal; and (II) an optical receiver unit for receiving the optical signal transmitted from the optical transmission unit comprising: an optical blocking means for blocking said optically modulated interference signal and for transmitting only said optically modulated television signal, whereby a non-subscriber having no blocking means receives both the optically modulated interference signal and the optically modulated television signal and thus is prevented from receiving the pay-channel television signal, and a subscriber having said blocking means is able to receive the pay-channel television signal, as well as the non-pay-channel television signal.
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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) | 1996-04-19 | 1996-10-19 | 1997-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-19 | 2000-10-19 | 2001-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-19 | 2004-10-19 | 2005-04-20 | $7700.00 | Window Closed / Lapsed |