The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 08, 1981
Filed:
Mar. 26, 1979
Shigeru Asakawa, Fujisawa, JP;
Makoto Nakamura, Kanagawa, JP;
Fumio Sugiyama, Sagamihara, JP;
Tsukasa Okai, Yokohama, JP;
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
A security communication system comprises a transmission apparatus including a scrambling circuit for scrambling an information signal according to a specific code and a reception apparatus including a deciphering circuit for deciphering an output signal of the transmission apparatus according to substantially the same code as the specific code. The transmission apparatus further includes a first signal generating circuit for supplying a synchronizing signal to the scrambling circuit to drive the same, a signal synthesizing circuit having a first input terminal coupled to the output terminal of the first signal generating circuit, and a switching circuit connected between the output terminal of the scrambling circuit and a second input terminal of the signal synthesizing circuit, said switching circuit being opened while the first signal generating circuit is generating a synchronizing signal. The reception apparatus further includes a second signal generating circuit and a synchronization circuit for supplying a drive signal to the deciphering circuit when the synchronizing signal component in the output signal of the transmission apparatus synchronizes with the output signal of the second signal generating circuit.