Title:
【発明の名称】スクランブル伝送方式
Document Type and Number:
Japanese Patent JP3028597
Kind Code:
B2
Abstract:
PURPOSE:To improve the ciphering effect by allowing a transmitter to apply phase processing to a picture signal in the horizontal direction in the unit of fields or lines in addition to scramble processing of a line in one field and allowing a receiver to restore the signal so as to make decoding of a ciphering signal difficult. CONSTITUTION:An A/D conversion circuit 11 of a transmitter 1 receives a picture signal S1 and converts it into a digital signal and a write address control circuit 12 applies phase processing to the signal and applies write processing to the resulting signal into a memory 15. A read analog control circuit 16 reads sequentially a signal written in the memory 15 according to an address of the memory 15. An A/D conversion circuit 21 of a receiver 2 receives a cipher signal S2 and converts it into a digital signal and writes it into a memory circuit 23. A read address control circuit 24 selects a descramble pattern of a descramble data storage circuit 25 in the case of read processing from the circuit 23 to convert a read vertical address. Thus, it is difficult to decode the cipher signal and the cipher effect is improved.
Inventors:
Minoru Harada
Application Number:
JP31972990A
Publication Date:
April 04, 2000
Filing Date:
November 22, 1990
Export Citation:
Assignee:
NEC
International Classes:
H04N1/44; G06F21/10; H04L9/28; H04L9/34; H04N7/167; (IPC1-7): H04N7/169; H04L9/34; H04N1/44
Domestic Patent References:
| JP2179042A |
Attorney, Agent or Firm:
Naotaka Ide