
US Patent No: 4,628,359
Number of patents in Portfolio can not be more than 2000
Memory selecting system for scrambled television receiver
Stats
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Dec 9, 1986
Issued date -
Mar 22, 1984
filing date -
06/592,257
serial no -
Expired
status
Importance
Abstract
A scrambled television program that is received and recorded in a scrambled fashion includes program code and corresponding key codes for use in descrambling the recorded scrambled signal. The program codes and key codes are retained in a memory so that upon reproduction the key code can be read out of the memory and fed to a descramble pattern generator for descrambling the reproduced scrambled signal. By placing the program code and key code at the end of the scrambled program the scrambled signal cannot be descrambled until the entire program has been first received. By dividing the memory into permanent and temporary memories and adding an identification code to the transmitted scrambled signal, which selects either the permanent or temporary memory, and counting the number of times that the temporary memory is read out there can be a limitation placed on the number of times that the scrambled program is reproduced and decoded for viewing. Once a selected number is reached the contents of the temporary memory are erased, thereby preventing descrambling of the reproduced signal.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
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| 4,460,922 Memory select system for an STV decoder | 77 | 1981 | |
| 4,514,761 Data encryption technique for subscription television system | 68 | 1982 | |
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| 4,278,837 Crypto microprocessor for executing enciphered programs | 428 | 1979 | |
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| 4,225,884 Method and system for subscription television billing and access | 174 | 1978 | |
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| 4,533,949 Subscription television system | 84 | 1982 | |