Signal transmission apparatus and signal transmission method

• US 7,231,042 B2
• Filed: 02/28/2001
• Issued: 06/12/2007
• Est. Priority Date: 02/29/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kori, Teruhiko, Ninoseki, Noriko
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Chen, Shin-Hon
• Application Number:
  US09/796,908
• Publication Number:
  US 20010037307A1
• Time in Patent Office: 2,295 Days
• Field of Search: 380/201, 380/203, 380/10, 380/20, 380/16, 386/94, 386/46, 386/96, 386/37, 360/60, 713/189, 713/151, 713/153, 713/165, 713/200, 713/201, 369/53.2, 726/26, 726 31- 33
• US Class Current: 380/201
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 2370/047 using display data channel standard [DDC] communication
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/4143 embedded in a Personal Computer [PC]
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

Copyright of contents to be transmitted may be protected for an analog signal produced by converting a digital signal representative of the contents. A signal transmission apparatus determines whether the contents are protected by copyright by detecting copyright protection information of a digital image signal of the contents at a protection information detecting unit, and scrambles an analog image signal converted from the digital image signal to output when the copyright is protected, or prohibits outputting of the analog image signal. When a receiving apparatus receives a transmitted signal, the apparatus generates a digital image signal and the analog image signal based on the transmitted signal. When the authentication processing unit of the receiving apparatus has determined that the copyright has been protected through communication between an authentication processing unit of the transmission apparatus and that of the receiving apparatus, the unit scrambles the analog image signal to output, or prohibits outputting thereof, or superimposes a-copy-guard signal on the image signal to output.

Claims

1. A signal transmission apparatus for transmitting a digital signal representative of contents of information to be transmitted as well as for converting the digital signal to an analog signal to output, wherein the analog signal is transmitted simultaneously with the digital signal through a single connector, the apparatus comprising:

a protection detecting part for determining whether the contents are protected by copyright; and

a transmission processing unit including a copyright protecting part for performing a copyright protection operation that alters the analog signal and the digital signal when the contents are determined as protected by copyright based on a result of the determination conducted by the protection detecting part, and

a transmitting part for transmitting the copyright protected analog and digital signals through said connector to at least one receiving apparatus.

2. A signal transmission apparatus according to claim 1, wherein the copyright protecting part includes a scrambling part for scrambling the analog signal, the copyright protecting part outputting and transmitting the analog signal scrambled by the scrambling part when the contents are determined as protected by copyright by the protection detecting part.

3. A signal transmission apparatus according to claim 1, wherein the copyright protecting part prohibits outputting and transmitting of the analog signal when the contents are determined as protected by copyright by the protection detecting part.

4. A signal transmission apparatus according to claim 1, wherein determination as to the copyright protection conducted by the protection detecting part is made based on copyright protection information transmitted together with the digital signal.

5. A signal transmission apparatus according to claim 4, wherein the protection detecting part retrieves copyright protection information embedded in the digital signal.

6. A signal transmission apparatus according to claim 4, wherein the digital signal is an image signal, and the protection detecting part retrieves copyright protection information multiplexed during a blanking period of the digital signal.

7. A signal transmission apparatus according to claim 4, wherein the protection detecting part determines that the contents are protected by copyright when a protection operating control signal to control copyright protection operation for an analog signal is transmitted as the copyright protection information.

8. A signal transmission apparatus according to claim 1, wherein determination of the copyright protection by the protection detecting part is based on copyright protection information transmitted via a signal line different from that of the digital signal.

9. A signal transmission apparatus according to claim 8, wherein the protection detecting part determines that copyright is protected when information indicative of the digital signal of the contents being encrypted is regarded as the copyright protection information.

10. A signal transmission apparatus according to claim 1, further comprising:

a signal converting part for converting a digital signal to an analog composite video signal when the digital signal of the contents is the image signal;

a signal generating part for generating a copy-guard signal; and

a signal adding part for superimposing the copy-guard signal on the composite video signal when the protection detecting part determines that the contents are protected by copyright.

11. A signal transmission method comprising the steps of:

determining whether contents of information to be transmitted are protected by copyright when a digital signal representative of the contents is transmitted; and

performing a copyright protection operation that alters the digital signal and an analog signal, said analog signal produced by converting the digital signal, when the contents are determined as protected by copyright, before the analog signal is outputted; and

transmitting simultaneously the copyright protected analog and digital signals through a single connector to at least one receiving apparatus.

12. A signal transmission method according to claim 11, wherein a scrambling processing is performed for the analog signal as the copyright protection operation.

13. A signal transmission method according to claim 11, wherein one of the outputting and the transmitting of the analog signal is prohibited via the copyright protection operation.

14. A signal transmission method according to claim 11, wherein determination of whether the contents are protected by copyright is made based on copyright protection information transmitted together with the digital signal.

15. A signal transmission method according to claim 14, wherein determination of whether the contents are protected by copyright is made by retrieving copyright protection information embedded in the digital signal.

16. A signal transmission method according to claim 14, wherein the digital signal is an image signal, and determination of whether the contents are protected by copyright is made by retrieving copyright information multiplexed during a blanking period of the digital signal.

17. A signal transmission method according to claim 14, wherein the contents are determined as protected by copyright when a protection operating control signal to control copyright protection operation for the analog signal has been transmitted as the copyright protection information.

18. A signal transmission method according to claim 11, wherein determination of whether the contents are protected by copyright is made based on copyright protection information transmitted via a signal line which is different from that of the digital signal.

19. A signal transmission method according to claim 11, wherein the contents are determined as protected by copyright when the digital signal of the contents is encrypted.

20. A signal transmission method according to claim 11, further comprising the steps of:

converting an image signal to an analog composite video signal when the digital signal of the contents is an image signal; and

superimposing a copy-guard signal on the composite video signal when the contents are determined as protected by copyright.

21. A signal transmitting apparatus for transmitting a digital signal representative of contents of information to be transmitted, comprising:

a conversion part for converting the digital signal to an analog signal to be outputted and transmitted simultaneously with the digital signal through a single connector;

a protection detecting part for determining whether the contents are protected by copyright;

a transmission processing apparatus including a copyright protecting part for performing a copyright protection operation that alters the digital signal and the analog signal when the contents are determined as protected by copyright based on a result of the determination conducted by the protection detecting part, and

a transmitting part for transmitting the copyright protected analog and digital signals through said connector to at least one receiving apparatus.

22. A signal transmission system comprising:

a signal transmitting apparatus for transmitting a digital signal representative of contents of information to be transmitted, comprising;

a conversion part for converting the digital signal to an analog signal to be outputted and transmitted simultaneously with the digital signal through a single connector;

a protection detecting part for determining whether the contents are protected by copyright;

a transmission processing unit including a copyright protecting part for performing a copyright protection operation that alters the digital signal and the analog signal when the contents are determined as protected by copyright based on a result of the determination conducted by the protection detecting part,

a transmitting part for transmitting the copyright protected analog and digital signals through said connector to at least one receiving apparatus; and

a signal receiving apparatus for receiving a digital signal representative of contents of information, comprising;

an authentication part for determining if the contents are protected by copyright;

a conversion part for converting a digital signal to an analog composite video signal when the digital signal of the contents is an image signal;

a signal generating part for generating a copy-guard signal; and

a signal adding part for superimposing the copy-guard signal on the composite video signal when the authentication part determines that the contents are protected by copyright.