| 摘要 |
PROBLEM TO BE SOLVED: To provide an image display device that can effectively prevent illegal acquisition and copying of an encrypted video signal with a comparatively simple method. SOLUTION: An authentication/decryption unit 2 authenticates and decrypts video signals received from a video signal output device 200. An open-condition detector 8 detects the open condition of a cabinet 10. A memory 7 stores therein one of a first flag indicating that an authentication operation of the authentication/decryption unit 2 is enabled and a second flag indicating that an authentication operation of the authentication/decryption unit 2 is disabled. A micro-controller 6 controls whether the authentication operation of the authentication/decryption unit 2 will be enabled or disabled according to the flag in the memory 7. When the open-condition detector 8 detects that the cabinet is opened, the micro-controller 6 writes the second flag into the memory 7. |
