Copyright information embedding apparatus
First Claim
1. A copyright information embedding apparatus comprising:
- A/D conversion means for converting an analog audio signal into a digital signal;
modulation means for modulating a copyright data signal for said digital signal using spectrum spread;
level detection means for detecting a variation in level of said digital signal; and
a copyright data embedding circuit embedding the copyright data signal into the digital signal when the variation in level of said digital signal detected by said level detection means shows a preselected variation.
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Accused Products
Abstract
A copyright information embedding system is provided which is designed to embed information for copyright protection into digital audio signals without deterioration of analog audio signals reproduced. The copyright information embedding system includes an A/D converter, a modulator, a level detector, and a copyright data embedding circuit. The A/D converter converts an analog audio signal into a digital signal. The modulator modulates a copyright data signal for the digital signal using spectrum spread. The level detector detects a variation in level of the digital signal. The copyright data embedding circuit divides the copyright data signal into several codes and embeds them into the digital signal each time the variation in level of the digital signal shows a preselected variation such as a rapid rise or drop.
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Citations
25 Claims
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1. A copyright information embedding apparatus comprising:
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A/D conversion means for converting an analog audio signal into a digital signal; modulation means for modulating a copyright data signal for said digital signal using spectrum spread; level detection means for detecting a variation in level of said digital signal; and a copyright data embedding circuit embedding the copyright data signal into the digital signal when the variation in level of said digital signal detected by said level detection means shows a preselected variation. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A record carrier comprising:
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a digital signal into which an analog audio signal is converted; and a copyright data signal carrying copyright information about said digital signal, modulated with spectrum spread, said copyright data signal being embedded into said digital signal each time a variation in level of said digital signal shows a preselected variation. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A copyright information embedding apparatus comprising:
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A/D conversion means for converting an analog audio signal into a digital signal; modulation means for modulating a copyright data signal carrying copyright information about said digital signal using spectrum spread; frequency detection means for detecting a frequency of said digital signal; and a copyright data embedding circuit embedding the copyright data signal into the digital signal at a preselected power level different from that of said digital signal. - View Dependent Claims (16, 17)
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18. A record carrier comprising:
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a digital signal into which an analog audio signal is converted; and a copyright data signal carrying copyright information about said digital signal, modulated with spectrum spread, said copyright data signal being embedded into said digital signal at a preselected power level different from that of said digital signal. - View Dependent Claims (19, 20, 21, 22)
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23. A copyright information embedding method comprising the steps of:
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A/D-converting an analog audio signal into a digital signal; modulating a copyright data signal for said digital signal using spectrum spread; detecting a variation in level of said digital signal; and embedding the copyright data signal into the digital signal when the variation in level of said digital signal detected by said level detection means shows a preselected variation.
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24. A copyright information embedding method comprising the steps of:
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A/D-converting an analog audio signal into a digital signal; modulating a copyright data signal carrying copyright information about said digital signal using spectrum spread; detecting a frequency of said digital signal; and embedding the copyright data signal into the digital signal at a preselected power level different from that of said digital signal.
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25. A copyright information embedding apparatus comprising:
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A/D conversion means for converting an analog audio signal into a digital signal; modulation means for modulating a copyright data signal for said digital signal using spectrum spread; level detection means for detecting a level of said digital signal; and a copyright data embedding circuit embedding the copyright data signal into the digital signal when the level of said digital signal detected by said level detection means lies within a preselected range.
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Specification