| 摘要 |
PROBLEM TO BE SOLVED: To always obtain a satisfactory transmission quality by preventing the occurrence of an instantaneous beat noise. SOLUTION: This method changes the light emission wavelengths of optical signals outputted from plural terminal stations 20 and multiplexes them to transmit them to an optical fiber 30 and receives this optical signal by a center station 10 to demodulate it. At this time, the center station 10 transmits a synchronizing clock signal from a clock oscillator 12 to each terminal station for the purpose of being synchronized with the terminal station, and each terminal station 20 obtains a scanning period of scanning lines of a monitor based on the clock signal taken in by a wavelength controller 26 and changes and controls the variance period of the light emission wavelength so that the period of the light emission wavelength of a light source 23 when the wavelength interval is narrowed to degrade the transmission quality coincides with the retrace time of scanning lines, thus preventing the occurrence of beat noise. |
