Method for superimposing and detecting additional information signal, method for detecting additional information signal, device for detecting additional information signal, and device for recording information signal

• US 6,204,981 B1
• Filed: 02/27/1998
• Issued: 03/20/2001
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ikeda, Nozomu, Ogino, Akira
• Primary Examiner(s): DAVIDSON, DAN
• Application Number:
  US09/031,717
• Time in Patent Office: 1,117 Days
• Field of Search: 360/60, 375/208, 380/3, 380/4, 380/5
• US Class Current: 360/60
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00913 based on a spread spectrum technique

Abstract

An additional information f2a previously superimposed repeatedly four times with a period shorter than the decoding period of a spread information on an information signal f1a by way of spectral spread is detected four times by way of an additional information signal detection section by way of inversion spread based on a spectrally spread PN signal f5a from a PN generation section, the coincidence detection section confirms coincidence of four detection results, and thus the superimposition of the additional information f2a is finalized, therefore the additional information f2a is detected within a short time because of a short period of the spectral spread, the additional information f2a is detected with high detection accuracy with a small spread gain by way of confirming the coincidence of four detections, and a write section can perform write inhibition properly based on detection of the additional information f2a.

Claims

1. A method for superimposing and detecting additional information in which an information signal is generated by superimposing said additional information on main information, said method for superimposing and detecting said additional information comprising the steps of:

superimposing repeatedly a plurality of times said additional information on said main information in order to generate said information signal;

detecting said additional information a plurality of detections; and

determining that said additional information is superimposed on said main information when said plurality of detections of said additional information are coincident.

2. The method for superimposing and detecting said additional information as claimed in claim 1, further comprising the step of controlling writing of said information signal in a recording medium.

3. The method for superimposing and detecting additional information as claimed in claim 1, wherein

said superimposing step of superimposing said additional information on said main information signal information includes spectrum spreading said additional information using a spread spectrum code; and

said step of detecting includes detecting said additional information by processing said information signal using an inverse spread spectrum generated from said spread spectrum code.

4. The method for superimposing and detecting said additional information as claimed in claim 1, further comprising the step of controlling an output of said information signal based on a result of said step of determining.

5. A device for superimposing and detecting additional information which generates an information signal by superimposing said additional information on main information and detects said additional information, said device for superimposing and detecting said additional information comprising:

information signal generation means for superimposing repeatedly a plurality of times said additional information on said main information in order to generate said information signal;

detection means for detecting said additional information a plurality of detections; and

determination means for determining that said additional information is superimposed on said main information when said plurality of detections of said additional information are coincident.

6. The device for superimposing and detecting additional information as claimed in claim 5, wherein

said information signal generation means superimposes said additional information on said main information signal by spreading said additional information using a spread spectrum code; and

said detecting means detects said additional information by processing said information signal using an inverse spread spectrum generated from said spread spectrum code.

7. The device for superimposing and detecting said additional information as claimed in claim 5, further comprising means for controlling writing of said information signal in a recording medium based on a result of said determination means.

8. The device for superimposing and detecting said additional information as claimed in claim 5, further comprising means for controlling an output of said information signal based on a result of said determination means.

9. An additional information detection device comprising:

a detector for receiving an information signal; and

a coincidence section coupled with said detector, wherein said detector detects an additional information signal superimposed on said information signal a plurality of times and said coincidence section outputs a signal indicating whether said plurality of times of detection of the additional information signal are coincident.

10. An additional information signal detection method in which an additional information signal is detected from an information signal generated by superimposing repeatedly a plurality of times said additional information signal on a main information signal, said additional information signal detection method comprising the steps of:

detecting said additional information signal with a plurality of detections; and

determining that said additional information signal is superimposed on said main information signal if said plurality of said detections of said additional information signal are coincident.

11. The additional information signal detection method as claimed in claim 10, further comprising the step of controlling writing of said information signal in a recording medium based on a result of said step of determining.

12. The additional information signal detection method as claimed in claim 10, further comprising the step of processing an inverse spread spectrum of the information signal using the spread spectrum code in order to detect said additional information at said step of detecting.

13. The additional information signal detection method as claimed in claim 10, further comprising the step of controlling an output of said information signal based on a result of said of determining.

14. An additional information signal detection device, which detects an additional information from an information signal generated by superimposing repeatedly a plurality of times additional information on a main information signal, said additional information detection device comprising:

detection means for detecting said additional information with a plurality of detections; and

determination means for determining that said additional information is superimposed on said main information signal when said plurality of detections are coincident.

15. The additional information signal detection device as claimed in claim 14, further comprising means for controlling writing of said information signal in a recording medium based on a result of said determination means.

16. The additional information signal detection device as claimed in claim 14, further comprising means for controlling an output of said information signal based on a result of said determination means.

17. The additional information signal detection device as claimed in claim 14, further comprising means for processing an inverse spread spectrum of said information signal using a spread spectrum code in order to detect said additional information at said detection means.

18. An information signal recording control device comprising:

a detection section for receiving and processing an information signal; and

a write control section coupled with said detection section, wherein said detection section detects an additional information signal superimposed on said information signal a plurality of times and outputs a signal indicating whether a plurality of detection results of the additional information signal are coincident, and whereby said write control section controls writing of said information signal in a recording medium according to said signal output from said detection section.