JPH0530113B

PURPOSE:To realize the transformation of an address code mixing device into an IC and to prevent the illegal use of the charged broadcast service by realizing the digital processing for formation of a total digital circuit. CONSTITUTION:A horizontal period of a prescribed field of the TV signal into which each bit of an address code is mixed is selected at pseudo random via an initialization processing means 7 and a PN code generating means 8. Then each bit of the address code can be put into a front pouch of the selected horizontal period in a digital form. As a result, the address code allocated to a terminal receiving device is always mixed into the TV signal outputted from said terminal receiving device. Thus a terminal equipment can be detected quickly, surely and easily in case an illegal copying action is performed via said terminal equipment. In such a way, the illegal use is prevented for the charged broadcast service and an address code mixing device is easily transformed into an LSI via the total digitalization.