Patent US5523173A successfully refreshed from Google Patents.
Patent US5617476A successfully refreshed from Google Patents.
US5617476A
Expired / Lapsed
US
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Audio scrambling system for scrambling and descrambling audio signals
Assignee: Panasonic Holdings Corp
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Filing: 1994-10-12
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Granted: 1997-04-01
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Expires: 2014-10-12
Abstract
Abstract A scrambling system has a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of 16-bit long sample data units. The scrambling apparatus has a detector for detecting, in each sample data unit, a meaningless portion which is a portion including the MSB and a meaningful portion which is a portion including the LSB, and applying scrambling only to the meaningful portion. Since the meaningless portion is not scrambled, no error data will appear in the meaningless portion. Thus, an unexpected abrupt change in sound caused by a bit error in the meaningless portion which has bits with greater weighted value can be avoided.
Inventors
- 👤 Susumu Ibaraki
- 👤 Noboru Katta
- 👤 Seiji Nakamura
- 👤 Hiroki Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:45
CPC Classifications
H; H04; H04K; H04K1/00; H04K1/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
169 words
A scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: first detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and said descrambling apparatus comprising: second detection means for detecting said first portion and said second portion in each scrambled sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; wherein said first portion and said second portion is separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant bit belonging to said first portion.
Claim 2
Dependent Claim
169 words
A scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: first detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and said descrambling apparatus comprising: second detection means for detecting said first portion and said second portion in each scrambled sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; wherein said first portion and said second portion is separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant bit belonging to said first portion.
Claim 3
Dependent Claim
197 words
A scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: first detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and said descrambling apparatus comprising: second detection means for detecting said first portion and said second portion in each scrambled sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; wherein said scrambling apparatus further comprises: memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said encryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 4
Dependent Claim
197 words
A scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: first detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and said descrambling apparatus comprising: second detection means for detecting said first portion and said second portion in each scrambled sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; wherein said scrambling apparatus further comprises: memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said encryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 5
Dependent Claim
44 words
A scrambling system according to claim 2, wherein said first detection means produces a masking signal having a first type data aligned at least a portion of said first portion and a second type data aligned at least a portion of said second portion.
Claim 6
Dependent Claim
21 words
A scrambling system according to claim 3, wherein said first type data is "0", and said second type data is "1".
Claim 7
Dependent Claim
50 words
A scrambling system according to claim 3, wherein said encryption means comprises: a scramble control signal generating means for generating a scramble control signal; and exclusive OR means for taking a logic exclusive OR between said scramble control signal and data in said second portion of said sample data unit.
Claim 8
Dependent Claim
109 words
A scrambling system according to claim 5, wherein said exclusive OR means comprises: an AND gate for taking a logic AND between said masking signal and said scramble control signal to permit said scramble control signal path therethrough where said second type data is present; a switch means for blocking said scramble control signal from said AND gate when said inhibit signal is present, and permitting said scramble control signal to path therethrough when said permit signal is present; and exclusive OR gate for taking a logic exclusive OR between said scramble control signal from said switch means and data in said second portion of said sample data unit.
Claim 9
Dependent Claim
123 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and wherein said first portion and said second portion are separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant belonging to said first portion.
Claim 10
Dependent Claim
123 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; and encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; and wherein said first portion and said second portion are separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant belonging to said first portion.
Claim 11
Dependent Claim
144 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said encryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 12
Dependent Claim
144 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said scrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; encryption means for encrypting said sample data unit only at said second portion, and for producing a scrambled sample data unit; memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said encryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 13
Dependent Claim
43 words
A scrambling apparatus according to claim 8, wherein said detection means produces a masking signal having a first type data aligned at least a portion of said first portion and a second type data aligned at least a portion of said second portion.
Claim 14
Dependent Claim
21 words
A scrambling apparatus according to claim 9, wherein said first type data is "0", and said second type data is "1".
Claim 15
Dependent Claim
50 words
A scrambling apparatus according to claim 9, wherein said encryption means comprises: a scramble control signal generating means for generating a scramble control signal; and exclusive OR means for taking a logic exclusive OR between said scramble control signal and data in said second portion of said sample data unit.
Claim 16
Dependent Claim
109 words
A scrambling apparatus according to claim 11, wherein said exclusive OR means comprises: an AND gate for taking a logic AND between said masking signal and said scramble control signal to permit said scramble control signal path therethrough where said second type data is present; a switch means for blocking said scramble control signal from said AND gate when said inhibit signal is present, and permitting said scramble control signal to path therethrough when said permit signal is present; and exclusive OR gate for taking a logic exclusive OR between said scramble control signal from said switch means and data in said second portion of said sample data unit.
Claim 17
Dependent Claim
124 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said descrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; and wherein said first portion and said second portion are separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant belonging to said first portion.
Claim 18
Dependent Claim
124 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said descrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; and decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; and wherein said first portion and said second portion are separated by a next-most-significant bit which is the highest order bit having a value which is not equal to that of a most-significant bit in said sample data unit, and said next-most-significant belonging to said first portion.
Claim 19
Dependent Claim
146 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said descrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; and memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said decryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 20
Dependent Claim
146 words
In a scrambling system comprising a scrambling apparatus and a descrambling apparatus for scrambling and descrambling a digital audio signal having a plurality of sample data units, each unit having a predetermined bit length, said descrambling apparatus comprising: detection means for detecting a first portion and a second portion in each sample data unit; decryption means for decrypting said scrambled sample data unit only at said second portion, and for producing a descrambled sample data unit; and memory means for storing a reserved code; comparator means for comparing a predetermined portion of said sample data unit with the same predetermined portion of said reserved code, and for producing a permit signal when said comparison result is a mismatch, and an inhibit signal when said comparison result is a match; and said decryption means being disabled by said inhibit signal and being enabled by said permit signal.
Claim 21
Dependent Claim
43 words
A descrambling apparatus according to claim 14, wherein said detection means produces a masking signal having a first type data aligned at least a portion of said first portion and a second type data aligned at least a portion of said second portion.
Claim 22
Dependent Claim
21 words
A descrambling apparatus according to claim 15, wherein said first type data is "0", and said second type data is "1".
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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) | 2000-03-31 | 2000-09-30 | 2001-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-31 | 2004-09-30 | 2005-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-31 | 2008-09-30 | 2009-04-01 | $7700.00 | Window Closed / Lapsed |