JPS6478536A - Multi-wave length digital transmission circuit - Google Patents

Abstract

PURPOSE:To dispose a transmission circuit and a reception circuit in close vicinity without necessitating a shield by adding a BPF respectively to the output of the encoding circuit of the transmission circuit and to the output of the light receiving element. CONSTITUTION:In the transmission circuit, input data is inputted to the encoding means 120 to execute to be able to eliminate a low frequency. The output of said encoding is inputted to the BPF 130 to let only a specific frequency band component pass through, and the output is transmitted to an optical fiber, etc., from a light emitting element driven by a light emitting element drive circuit. On the other hand in the reception circuit, the data is received by a light receiving element, converted to data of electrical signals, then inputted to the BPF 190 where only the specific frequency band component is allowed to pass. By making the pass bands of the BPF 130 and the BPF 190 different from each other, the leaking of the data in the transmission circuit into the reception circuit that causes a leakage error rate can be prevented.