| 摘要 |
PROBLEM TO BE SOLVED: To prevent unauthorized viewing by detecting an IC card connected to the digital broadcast receiver unauthorized and disconnecting the IC card. SOLUTION: This digital broadcast receiver 1 consists of a receiver main body 3 and IC cards 5, 7 which connect to/disconnect from the main body 3. A test signal multiplexer circuit 101 multiplexes a test input signal on a broadcast signal at a pre-stage of the IC cards in daisy chain connection. Test signal processing circuits 107, 108 in the IC cards 5, 7 apply prescribed processings to the test signal to output a test output signal. The test output signal detected by a test signal detection circuit 102 is given to a discrimination circuit 106, where the signal is compared and discriminated with a collect solution value. When the test result indicates a failure, switches 1009, 1010, 1011, 1012 corresponding to the relevant IC cards are switched to bypass the IC cards and to suppress an output of the broadcast signal to the IC cards. |
