| 摘要 |
PURPOSE:To prevent unjust reception by storing an address specific to a pay television receiver to a ROM and also storing a fixed address and a logical address for the purpose of reception of a special program to a customer's RAM. CONSTITUTION:A signal transmitted from a pay television managing device is inputted to a frequency converter 8 via a directional coupler 6 and a distributor 7, and after the frequency is decreased at the converter 8, the result is fed to the television receiver via a distributor 9 and a horizontal period restoration circuit 10. In viewing a special program, a one-chip microcomputer 13 reads a specific address of the pay television receiver 4 from a ROM17 and an FM reception circuit 11 compares it with a demodulated fixed address. When the both are coincident, the fixed address and the logical address for the reception of special program are stored in a RAM15. If the fixed address stored in the RAM15 and the fixed address in the ROM17 are different, the logical address is disabled so as to prevent almost perfectly unjust reception. |
