Invoicing system for pay TV sets - transmits cost information code signals in frame flyback time and controls accumulator reading via normal telephone connection

摘要

The invoicing system is for subscribers to pay-television services where the user pays only for the programmes watched. The cost of programmes can vary, a register or accumulator at the subscriber end providing a record readable by the TV centre at suitable intervals. Code signals providing the required cost information are included with the image transmission in the frame flyback time. Periodic accumulator reading is controlled by the central station via a telephone connection by transmitting interrogation signals without interrupting the telephone or viewing service to the viewer, the coded cost being read back to the central station.