Pay-tv time purchase scheme

• US 5,070,400 A
• Filed: 01/19/1989
• Issued: 12/03/1991
• Est. Priority Date: 06/30/1987
• Status: Expired due to Term

• Current Assignee: COMSAT Corporation (Reorganized ISA SA)
• Original Assignee: COMSAT Corporation (Reorganized ISA SA)
• Inventors: Lieberman, Daniel
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Chan, Wing F.
• Application Number:
  US07/300,701
• Time in Patent Office: 1,048 Days
• Field of Search: 358/84, 358/349, 380/10, 380/16, 380/20, 455/2, 455/4
• US Class Current: 725/151
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309

Abstract

A pay television subscriber pays for viewing credits which are transmitted to the subscriber equipment from a central office. Each program is associated with a pulse having a rate corresponding to the charge per unit time for that program, and the viewing credits are debited appropriately.

Claims

1. In a subscriber television system wherein multiple programs are transmitted from a central station to a plurality of subscribers at respective subscriber stations:

storage means at each subscriber station for storing viewing credit data representing viewing credit;

means for generating a debit signal in accordance with a fee associated with a program currently being viewed by a subscriber at each said subscriber station;

means for debiting said stored viewing credit data in accordance with said debit signal;

means for examining said stored viewing credit to see if it has been updated; and

means for disabling viewing if the stored viewing credit data has not been updated.

2. In a subscriber television system wherein multiple programs are transmitted from a central station to a plurality of subscribers at respective subscriber stations:

storage means at each subscriber station for storing an amount of data representing viewing credit, with the viewing credit corresponding to the number of memory locations at which the data are stored;

means for generating a debit signal in accordance with a fee associated with a program currently being viewed by a subscriber at each said subscriber station; and

means for decreasing the amount of said stored data in accordance with said debit signal.

3. A system as defined in claim 2, wherein said debiting means erases said data at a rate in accordance with said debit signal.

4. A system as defined in claim 2, further comprising monitoring means at each said subscriber station for determining whether said means for decreasing at that subscriber station is operating properly, and means responsive to said monitoring means for disabling viewing if said means for decreasing is not operating correctly.

5. A system as defined in claim 2, wherein said debiting means comprises means for successively changing the contents stored at successive addressed locations, said system further comprising means for determining if the contents of a presently addressed location have been changed and means for disabling viewing if said presently addressed location have not been changed.

6. A system as defined in claim 2, wherein said storage means comprises first and second memories each for storing credit data, and said debiting means comprises means for erasing data from one of said first and second memories until said one memory is empty and for thereafter erasing data from the other of said memories.

7. A system as defined in claim 2, wherein said storage means comprises a non-volatile memory.

8. A system as defined in claim 7, wherein said memory comprises an EEPROM.

9. A system as defined in claim 2, wherein said debiting signal comprises a pulse generated at a rate corresponding to the charge for a particular program being viewed.

10. A system as defined in claim 9, wherein said rate of said pulse is determined by a control signal sent from said central station.

11. A system as defined in claim 10, wherein said control signal is sent from said central station at a rate corresponding to said pulse rate.

12. A system as defined in claim 2, further comprising means at each said subscriber station for adding data to said stored viewing credit data in response to a fill control signal sent from said central station.

13. A system as defined in claim 12, further comprising means at each said subscriber station for visually indicating to said subscriber the date of the most recent memory fill operation.

14. A system as defined in claim 2, wherein said debiting means comprises means for generating successive memory addresses, said system further comprising:

first comparing means for comparing generated addresses separated by a predetermined time interval; and

disabling means for disabling viewing if the compared addresses are not different from one another.

15. A system as defined in claim 14, wherein said debiting means further comprises means for successively changing the contents stored at successive addressed locations, said system further comprising means for determining if the contents of a presently addressed location have been changed, with said disabling means disabling viewing if said compared generated addresses are not different or if said contents of said currently addressed location have not been changed.