Receiver and receiving method

• US 20060023881A1
• Filed: 02/22/2005
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Akiyama, Hitoshi, Tonami, Katsuhiko
• Granted Patent: US 7,590,241 B2
• Time in Patent Office: Days
• US Class Current: 380/210
• CPC Class Codes: H04H 20/76 Wired systems
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04H 60/23 using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04N 21/43853 involving multiplex stream decryption arrangements using cryptography for the use of broadcast information or broadcast-related information H04H60/23
• CPC Class Codes: H04N 7/163 by receiver means only

Abstract

When a channel which is not scrambled is selected, an error occurs in a digital stream processed in a CA processing module, which causes noises to occur in video and audio signals to be viewed. If a FAT channel to be received is a channel that is not CA-scrambled, a digital stream is directly supplied from a FAT demodulator to a demultiplexer without passing the digital stream through an external processing module. As a result, no noise occurs in video and audio signals to be viewed because the video and audio signals are not influenced by an error of the digital stream that occurs in the processing module.

Claims

1. A receiver for receiving a broadcast signal that includes a program signal and an encryption information signal relating to the program signal, said receiver comprising:

first receiving module to receive the program signal;

second receiving module to receive the encryption information signal relating to the program signal;

decryption module to decrypt the program signal received by the first receiving module;

detection module to detect the encryption information signal relating to the program signal received by the second receiving module; and

output module to, on the basis of the encryption information signal relating to the program signal detected by the detection module, output either the program signal coming from the first receiving module or the program signal coming from the decryption module.

2. A receiver according to claim 1, said receiver further comprising:

encryption module to encrypt the program signal, which has been decrypted by the decryption module, in a manner different from that at the time of broadcasting; and

second decryption module to decrypt the program signal encrypted by the encryption module.

3. A receiver according to claim 1, wherein:

on the basis of the encryption information of the program signal detected by the detection module, said output module makes a judgment as to whether or not the program signal is scrambled, and if it is judged that the program signal is scrambled, said output module outputs a program signal that has passed through the decryption module, whereas if it is judged that the program signal is not scrambled, said output module outputs a program signal coming from the first receiving module.

4. A receiver according to claim 1, said receiver further comprising:

demultiplexing module to demultiplex the program signal output from the output module;

decoding module to decode the program signal demultiplexed by the demultiplexing module; and

an image receiver to display the program signal decoded by the decoding module.

5. A receiver according to claim 1, said receiver further comprising:

second encryption module to encrypt the program signal output from the output module, said program signal being encrypted when the program signal is output to an external device; and

an external-device output unit to output to the external device a signal encrypted by the second encryption module.

6. A receiver according to claim 5, wherein:

on the basis of the encryption information of the program, said external-device output unit makes a judgment as to whether or not the program is scrambled, and if it is judged that the program is scrambled, said external-device output unit outputs a signal coming from the second encryption module, whereas if it is judged that the program is not scrambled, said external-device output unit outputs a signal output from the output module.

7. A receiver according to claim 1, said receiver further comprising:

a first demultiplexer to demultiplex the program signal received by the first receiving module; and

a second demultiplexer to demultiplex the program signal output from the decryption module,

wherein;

on the basis of the encryption information signal relating to the program signal, said output module outputs either the program signal demultiplexed by the first demultiplexing module or the program signal demultiplexed by the second demultiplexing module.

8. A receiver according to claim 7, said receiver further comprising:

decoding module to decode the program signal demultiplexed by the first demultiplexing module or the second demultiplexing module to output the decoded program signal to the output module.

9. A receiver according to claim 8, said receiver further comprising:

image receiving module to display data that has been demultiplexed by the first demultiplexing module or the second demultiplexing module, and that has then been decoded by the decoding module.

10. A receiver for receiving a broadcast signal that includes a program signal and an encryption information signal relating to the program signal, said receiver comprising:

first receiving module to receive the program signal;

second receiving module to receive the encryption information signal relating to the program signal;

an output unit to output, to an external device, an output signal output from the first receiving module and an output signal output from the second receiving module;

an input unit to input a signal that includes the program signal coming from the external device, and an encryption information signal relating to the program signal; and

output module to, on the basis of the encryption information signal relating to the program signal that has been detected by the external device and has been inputted through the input unit, output either the program signal from the first receiving module or the program signal decoded in the external device, said decoded program signal coming from the external device and being inputted through the input unit.

11. A receiver according to claim 10, wherein:

on the basis of the program encryption information inputted through the input unit, said output module makes a judgment as to whether or not the program is scrambled, and if it is judged that the program is scrambled, said output module outputs a decrypted signal inputted through the input unit, whereas if it is judged that the program is not scrambled, said output module outputs the program signal coming from the first receiving module.

12. A receiver according to claim 10, said receiver further comprising:

second decryption module to decrypting the program signal inputted from the input unit, said program signal being encrypted in a manner different from that at the time of broadcasting.

13. A receiver according to claim 10, said receiver further comprising:

demultiplexing module to demultiplex the program signal output from the output module;

decoding module to decode the program signal demultiplexed by the demultiplexing module; and

an image receiver to display the program signal decoded by the decoding module.

14. A receiver according to claim 10, said receiver further comprising:

second encryption module to encrypt the signal output from the output module; and

an external-device output unit to output to the external device a signal encrypted by the second encryption module.

15. A receiver according to claim 14, wherein:

on the basis of the encryption information of the program, said external-device output unit makes a judgment as to whether or not the program is scrambled, and if it is judged that the program is scrambled, said external-device output unit outputs a signal coming from the second encryption module, whereas if it is judged that the program is not scrambled, said external-device output unit outputs a signal output from the output module.

16. A receiving method for receiving a broadcast signal that includes a program signal and an encryption information signal relating to the program signal, said receiving method comprising:

a first receiving step for receiving the program signal;

a second receiving step for receiving the encryption information signal relating to the program signal;

a decryption step for decrypting the signal received in the first receiving step;

a detecting step for detecting the encryption information signal relating to the program received in the second receiving step; and

an outputting step for, on the basis of the encryption information signal relating to the program signal detected in the detecting step, outputting either the signal received in the first receiving step or the signal decrypted in the decryption step.

17. A receiving method according to claim 16, wherein:

on the basis of the encryption information of the program signal detected in the detecting step, said outputting step makes a judgment as to whether or not the program signal is scrambled, and if it is judged that the program signal is scrambled, said outputting step outputs a program signal that has passed through the decryption step, whereas if it is judged that the program signal is not scrambled, said outputting step outputs a program signal received at the first receiving step.

18. A receiving method for receiving a broadcast signal that includes a program signal and an encryption information signal relating to the program signal, said receiving method comprising:

a first receiving step for receiving the program signal;

a second receiving step for receiving the encryption information signal relating to the program signal;

an outputting step for outputting, to the external device, the signal received in the first receiving step and the signal received in the second receiving step;

an inputting step for inputting a signal that includes the program signal coming from the external device, and an encryption information signal relating to the program signal; and

an outputting step for, on the basis of the encryption information signal relating to the program signal that has been detected by the external device and has been inputted in the inputting step, outputting either the program signal received in the first receiving step or the program signal decrypted on the basis of the encryption information signal, said decrypted program signal coming from the external device and being inputted in the inputting step.

19. A receiving method according to claim 18, wherein:

on the basis of the program encryption information inputted in the inputting step, said outputting step makes a judgment as to whether or not the program is scrambled, and if it is judged that the program is scrambled, said outputting step outputs a decrypted signal inputted in the inputting step, whereas if it is judged that the program is not scrambled, said outputting step outputs the program signal received in the first receiving step.