US4630112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Descrambling apparatus for a television signal
Assignee: Hitachi Ltd
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Filing: 1983-11-18
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Granted: 1986-12-16
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Expires: 2003-11-18
Abstract
Abstract In an apparatus for descrambling a scrambled television signal, an elastic surface wave filter is used. This elastic surface wave filter has an interdigital electrode having an electrode pattern similar to at least portion of the waveforms of a luminance signal section of the scrambled television signal to be input. The elastic surface wave filter generates a response pulse only when the waveforms which are analogous to the electrode pattern of the interdigital electrode of the scrambled television signal were input, thereby descrambling the television signal using this response pulse.
Inventors
- 👤 Jun Yamada
- 👤 Takeshi Murakami
- 👤 Akitsuna Yuhara
- 👤 Norio Hosaka
- 👤 Yuji Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:49
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/167; H04N7/1675; H04N7/171; H04N7/1713
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
105 words
An apparatus for descrambling a scrambled television signal in which the scrambling has been effected by modifying a cyclically generated signal section to have a particular multi-level shape, comprising: input means for inputting the scrambled television signal; filter means, connected to said input means, for generating a response signal only when each level of a multi-level portion of a waveform having said particular shape of said cyclically generated signal section of the scrambled television signal received from said input means is detected; and conversion means for converting the scrambled signal in response to said response signal of said filter means into a descrambled television signal.
Claim 2
Independent Claim
105 words
An apparatus for descrambling a scrambled television signal in which the scrambling has been effected by modifying a cyclically generated signal section to have a particular multi-level shape, comprising: input means for inputting the scrambled television signal; filter means, connected to said input means, for generating a response signal only when each level of a multi-level portion of a waveform having said particular shape of said cyclically generated signal section of the scrambled television signal received from said input means is detected; and conversion means for converting the scrambled signal in response to said response signal of said filter means into a descrambled television signal.
Claim 3
Dependent Claim
48 words
A descrambling apparatus according to claim 1, wherein said filter means is an elastic surface wave filter having an interdigital electrode structure with a pattern shape similar to at least a portion of the waveforms of said signal section of particular multi-level shape of said scrambled television signal.
Claim 4
Dependent Claim
36 words
A descrambling apparatus according to claim 2, wherein the pattern shape of said interdigital electrode is analogous to at least a portion of a luminance signal section which is cyclically generated in said scrambled television signal.
Claim 5
Dependent Claim
40 words
A descrambling apparatus according to claim 1, wherein said conversion means includes means for inputting said scrambled television signal as a signal to be modulated and for utilizing the response signal from said filter means as modulation for said 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) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |