| 摘要 |
<P>PROBLEM TO BE SOLVED: To preserve proper transmission quality, regardless of the relative distance in an optical transmission system for receiving light from a light-emitting unit of a transmission device at a light-sensitive unit of a receiving device, to obtain information between the transmission device and the receiving device which are arranged with the relative distance variable. <P>SOLUTION: Optical signal intensity received by the light-sensitive unit 210 of the receiving device 200 rises by narrowing the distance between the transmission device 100 and the receiving device 200. Then, a distortion-generating distance, resulting from the narrowing, is determined at which the distortion is generated in a received signal at the receiving device 200. Further, in the receiving device 200, there is provided a narrowing detection light-emitting means for generating light which can travel through the distortion generating distance resulting from the narrowing. Furthermore, in the transmission device 100, there is provided a narrowing detection light-sensitive means for sensing light from the narrowing detection light-emitting means. When the narrowing detection light-sensitive means has sensed light from the narrowing detection light-emitting means, the transmission device 100 makes the emission intensity of the light-emitting unit 150 for transmitting information decrease through optical communication. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
