| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a system which realizes high-speed spatial optical transmission with a simple structure. <P>SOLUTION: When adjusting the position of a mobile terminal 30, an optical transmitter 10 irradiates an optical-axis alignment light in a wide beam angle through an optical beam diameter controller 20. The mobile terminal 30 has a light receiving element 32 for receiving data light, and four light receiving elements 34A to 34D for determination of the optical axis surrounding it. A comparison/computing apparatus 36 calculates vector values that indicate deviations of the optical axis for an optical-axis alignment light based on outputs from the light receiving elements 34A to 34D to transmit them to a controller 38. The controller 38 displays an arrow that has a length and a direction corresponding to the vector values calculated by the comparison/computing apparatus 36 on a screen of a monitor 40. When deviation of the optical axis of the optical-axis alignment light becomes small, the controller 38 allows a radio transmitter 44 to transmit transmissible signals to an optical transmitter 10. Corresponding to the transmissible signals, a controller 14 transmits data to the mobile terminal 30, using data light of beam diameter adjusted by the optical beam diameter controller 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
