| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical transmitting circuit performing not only a correction to a temperature change of a light-emitting device but also to other factors such as a time varying change of a light-emitting device. SOLUTION: A pulse driving circuit 42 controls light emitting of a semiconductor light-emitting device 44 corresponding to a transmitting signal 41 so as to transmit optical signals. A part thereof is detected by a photodetecting element 46 for being converted into a voltage by means of a preliminary amplification circuit so as to be compared with a reference voltage by a comparator 53. A control circuit 43 checks whether or not it is a voltage corresponding to the transmitting signal 41 and when it is discriminated to have lowered light emitting, a parameter signal 57 to be delivered to an operation circuit 56 is changed. The operation circuit 56 performs operation correcting the light- emitting characteristics according to a temperature sensor 47 detected a temperature of the semiconductor light-emitting device 44 and also deals so as to stabilize the light-emission level also to other facrors than the temperature by the parameter signal 57. |
