| 摘要 |
PURPOSE:To obtain a light distribution system of very high flexibility by measuring optical signals of one side branched by a fixed light quantity branching device and controlling a variable light quantity branching device so that the optical signals become of a prescribed quantity of light. CONSTITUTION:The optical signal outputted to an optical fiber 27 is received by a light receiver 29 in a control circuit 28, and its quantity of light is measured. Since the light quantity branching ratio of the fixed light quantity branching device 26 is fixed, the quantity of light outputted to a light output line 22 can be easily estimated from the quantity of light measured by the light receiver 29. Next, in the case that the light receiver, etc., is connected to the light output line 23, the control circuit 28 compares the quantity of light received by the light receiver 29 with estimated quantity of light set beforehand. When the quantity of light received by the light receiver 29 exceeds the estimated quantity of light as the result, the light quantity branching ratio of the variable light quantity branching device 24 is changed, and the quantity of light to be distributed to the optical fiber 25 is decreased, and in the case that the said quantity of light is less than the estimated quantity of light, such control that the light quantity branching ratio of the branching device 24 is changed and the quantity of light to be distributed to the optical fiber 25 is increased. Thus, the light distribution system of the high flexibility is obtained. |
